New Cadillac president Johan de Nysschen poses with an ATS-V in Los Angeles last month. De Nysschen has wasted no time in laying out an audacious global vision for GM's old luxury brand. Source: General Motors Company.

The revival of General Motors' (GM -0.05%) luxury Cadillac brand was one of the big stories in the auto business last year. The old brand's U.S. sales rose 21.9% last year, thanks to strong new models that drew big praise from critics. 

But this year has been a very different story. Through November, Cadillac's U.S. sales are down 5.9% -- even as other luxury brands have set new sales records.

What's the deal? The deal is that Cadillac's problems run much deeper than last year's sales success would suggest. The good news is that Cadillac has a strong new leader, longtime Audi executive Johan de Nysschen, who understands those problems and knows what to do about them.

De Nysschen reports to GM President Dan Ammann, and Ammann and CEO Mary Barra have promised de Nysschen something nearly unprecedented in GM's history: the budget, the leeway, and the patience needed to do everything necessary to turn Cadillac into a top global luxury brand.

And one of the things de Nysschen is determined to work on is Cadillac's dealer network.

Why dealers are a problem and an opportunity for Cadillac
What's the problem with Cadillac's U.S. dealer network? There are several problems, de Nysschen said in a presentation to Wall Street analysts last month.

First, there are a lot of Cadillac dealers in the United States: 925, almost three times as many as rival BMW (BAMXF -0.19%) has here. That arguably makes Cadillac seem like a less exclusive brand than BMW, and it definitely hurts the profitability of each of those dealerships relative to BMW's.

Why? Because each store ends up selling fewer cars. Consider: Last year, Cadillac sold 182,540 vehicles in the U.S. That works out to an average of 197 per store. Meanwhile, BMW's 339 U.S. dealers sold 309,280 vehicles last year, or about 912 per dealership -- or put another way, over four times as many

That's a huge difference in average profitability per store. 

But dealers are franchise-holders, not part of GM or Cadillac itself. Why does Cadillac care? There are lots of reasons that GM (or any automaker) should care a great deal about the health of its dealers, but here's a big one that's especially important in the luxury market: A dealer selling fewer cars is less likely to be willing or able to invest in the services and amenities that luxury-car customers demand.

The new-for-2015 Cadillac Escalade has moved sharply upscale. Not just in price (it's up almost $4,000), but in features and market positioning, as this GM publicity photo shows. It's working: While sales of Cadillac's sedans are down, Escalade sales have risen more than 50% this year. Source: General Motors Company.

De Nysschen feels that Cadillac dealers are far behind Toyota's Lexus and the big three German luxury brands in terms of overall customer experience. That relates to everything from the dealerships' decor to their level of customer-service technology -- but in particular, he feels that Cadillac dealers have trouble attracting top-notch sales and service talent.

That's a big issue. In the ATS and CTS, Cadillac finally has two models that are credible, appealing alternatives to the German-brand stalwarts. That should be enough to entice some BMW or Audi owners to switch. But so far, those buyers haven't materialized in significant numbers

As de Nysschen sees it, the German-brand loyalists might be tempted to check out a Cadillac, but they lose interest once they encounter the current reality of (many) Cadillac dealerships, where the sales representatives may not have the experience or talent to successfully represent Cadillac's latest products in the way that BMW or Mercedes-Benz owners have come to expect.

GM itself is part of the problem here, too
Having too many dealers is part of the problem, but de Nysschen says that another big factor is that many of those dealers are in the wrong places:

It is a policy at General Motors that when you have common ownership of stores of the various brands of the corporation that we want them to cohabitate. So it's against the company's policy to let a Cadillac store, for example, be positioned next door to a BMW store owned by the same dealer. We want the family to be together.

Now there are, I'm sure, very good merits for that if you are running Chevrolet, GMC, or Buick. But what you do when you execute that policy for Cadillac is that you put the brand in an environment where luxury shoppers don't want to go. And if you want to exercise synergies and back-office shared services and whatever, it trickles down and you end up selling Cadillac out of the back door of the Chevy store.

And I will tell you, no BMW owner would want to go look for a Cadillac there.

Ouch. So how will de Nysschen address this problem? 

Will GM start closing Cadillac dealers?
Cutting the number of dealerships would be one obvious solution to all of these problems. Reducing the number of Cadillac dealerships would instantly make most of the survivors more profitable -- and even the threat of elimination might motivate dealers to spend money on the upgrades de Nysschen wants to see. 

But as GM discovered when it eliminated the Oldsmobile brand, closing dealerships is an expensive hassle. New-car dealers are independent businesses protected by a myriad of state laws. Many have been locally owned family businesses for generations, and they've amassed considerable political clout. GM would likely have to buy out several hundred dealers, a project that could cost billions and take a year or more -- a year in which a lot of hard feelings might be generated.

The new-for-2014 Cadillac CTS sedan has received wide critical acclaim -- but sales are down. One problem: The CTS competes directly with BMW, but many of Cadillac's dealers aren't yet up to BMW standards. That may be driving potential buyers elsewhere. Source: General Motors Company.

It's possible that GM will eventually decide it needs to trim Cadillac's dealer ranks despite the cost and hassle. But even if that's what de Nysschen and GM are planning, I wouldn't expect them to announce it until it's actually happening, and de Nysschen gave no hints that such a project was in the works. On the contrary, he laid out several ideas for making the most of the brand's existing network.

He argued, for instance, that Cadillac's large number of dealers gives it representation in smaller markets that its competitors might miss. Some of those smaller-market dealerships could be transformed into "boutique" stores that could operate profitably while still representing the brand well, he said. 

But GM can help its dealers raise their games in other ways. De Nysschen hinted at a new dealer-bonus system that would provide incentives for activities that helped support the brand. And the ongoing effort to raise Cadillac's average transaction prices will help dealers make more money per sale, and that in turn can boost their enthusiasm for the brand and spur investment.  

Cadillac's average transaction prices are already up about $5,000 this year, even as its U.S. sales have fallen. Audi's recent experience suggests that could help boost dealer investment: Trade publication Ward's Auto recently noted that Audi's average transaction prices have risen roughly $9,600 per unit over the last five years, and its U.S. dealer body has collectively invested about $1 billion in upgrades over the same period. Audi has about 280 U.S. dealers. And some investments have already been made: Cadillac spokesman David Caldwell said via email that about half of the brand's U.S. dealers have already upgraded their facilities to GM's latest standard, including many in key metropolitan markets.

Nysschen thinks that GM can also help its Cadillac dealers boost their revenues from used-car sales -- in a way that helps the brand. Cadillac, like most automakers, has a "certified pre-owned" program for used cars. Not all dealers have a significant used-Cadillac operation, but de Nysschen thinks they should: It can be a significant source of profits for a dealer -- the average profit per sale can exceed that of new-vehicle sales.

The upshot: Big changes are coming to the way Cadillac sells cars
GM has been talking about raising Cadillac's game for years. But in de Nysschen, it finally has a leader who knows what to do, along with the power to get it done.

For a while now, Cadillac's challenge has been that its cars have improved to the point where they can compete with the Germans, but the brand itself hasn't made the same progress.

Improving Cadillac's U.S. dealer network has the potential to do a lot of good for the way the brand is perceived by luxury-minded customers.

It's just one step in many that de Nysschen has planned for Cadillac. But it's an important and very visible one. GM shareholders will be watching this one closely.