I took a look yesterday at the many challenges facing the merger between XM Satellite Radio (Nasdaq: XMSR) and Sirius Satellite Radio (Nasdaq: SIRI). There certainly are many, even in a post-merger world, and that includes many eardrum magnets that I didn't get around to singling out, like new cars coming with hard drives and Garmin (Nasdaq: GRMN) GPS systems offering MP3 and audiobook playback.

Today I'm going to go over the opportunities that exist in the coming years for Sirius-XM, which is now just an FCC nod away from regulatory approval.

1. Billions in synergies
Satellite radio is as close as you can get to a scalable model. Between the high fixed overhead and the low variable costs, the income statements put out by Sirius-XM in the future will look far better than the ones you see today. Going from a pair of companies with 9 million-ish subscribers apiece to one player with 17.3 million subscribers is going to make a huge difference.

Citi analyst Eileen Furukawa pegged the cost savings to be as much as $7.2 billion a year. Between the cutting of operating redundancies, reduced marketing expenses, and greater programming leverage, CEO Mel Karmazin will have a lot more wiggle room to dream out loud.

2. The used-car revolution
We're now at the point where the first wave of cars with satellite radio receivers are being traded in. This represents an ideal opportunity for cheap customer acquisitions, since the receivers have already been paid for.

With Sirius-XM committed to introducing a lower-priced tier within a year of the deal's completion, the $6.99 a month plan for 50 nonpremium channels may resonate with thrifty car owners who can't justify -- or pay for -- the current take-it-or-leave-it $12.95 aural buffet.

3. Video thrilled the radio star
One of the more intriguing developments out of the satellite radio camp was when Sirius launched a backseat video option last year. Road-trip dads and soccer moms no longer need to fumble for DVDs to play on backseat video monitors if they pay to have Sirius stream three kid-friendly television channels.

It's not a perfect product. The iffy compressed quality makes it a good fit for animated fare for undiscerning children, but that's often all you need to make a long drive go smoother. It remains to be seen if this will catch on, or how Sirius can expand on it, but it's a great way for satellite radio to collect more than its monthly $13 ransom.

4. Brand on the run
There are opportunities even in some of the challenges. Yes, Nokia (NYSE: NOK) is starting to market handsets that come with music subscription plans included. Apple's (Nasdaq: AAPL) iPhone is bridging the gap between communication and entertainment. This doesn't mean that a smartphone heavy won't side with XM or Sirius to put out a branded phone that doubles as a satellite receiver. They may as well, before Sirius-XM beats them all to the punch and does it on its own.

Yes, a company that looks after 17.3 million on-the-go subscribers with the disposable income to pay for satellite radio provides a juicy target audience for any handset maker. Now that Sirius-XM will have two brands, it can conceivably strike two deals. Would you like a Sirius iPhone or is an XM BlackBerry more to your liking?

Wouldn't a Kindle be that much more valuable if it also provided satellite radio playback?

5. The marketing muscle
Sirius and XM have been slow in growing their ad revenues. That may very well be why you love your satellite radio, given the commercial-free music channels and limited ads on the talk channels.

Am I suggesting that the future of Sirius-XM will be as ad-plastered as terrestrial radio? No way. However, the next generation of satellite receivers -- beyond offering interoperability -- will be more useful to marketers. Interactive features will allow subscribers to purchase songs they are listening to or request additional information from advertisers. In the end, it will create ways for Sirius-XM to generate more money through new revenue channels. In my "Sirius in 2010" article, I even predicted that an audio shopping channel will be a top satellite radio draw.

Beyond new receivers, you also have enhanced sponsorship opportunities by milking more online ad revenue -- something that is sorely untapped on both the XM and Sirius websites for now -- and company-branded channels. Branded channels? Why not? If every sports stadium has a corporate sponsor paying for naming rights, why not the dozens of brandable satellite radio channels? The Starbucks (Nasdaq: SBUX) relationship didn't work out too well for XM, but Sirius-XM is now in a position to command money for those rights instead of it having to shell out money for exposure.

Sirius-XM has come a long way, and now it's time to see healthier top lines enhance the better-looking bottom lines.

More about the courtship of XM and Sirius:

Apple, Garmin, and Starbucks are Motley Fool Stock Advisor newsletter selections. Garmin is also a Global Gains pick, and Starbucks is also an  Inside Value pick. The Motley Fool owns stock in Starbucks. Take a free trial to any of these newsletters; complete access for 30 days.

Longtime Fool contributor Rick Munarriz is such a big satellite radio fan that he subscribes to both XM and Sirius. He does not own shares in any of the companies in this story. He is a member of the Rule Breakers analytical team, seeking out the next great growth stock early in its defiance. The Fool has a disclosure policy.