It's over. The government's "cash for clunkers" rebate program hit the brakes last night. There will be no more $4,500 discounts on trade-ins being swapped for new cars with better mileage.

This doesn't mean that the program has to come to a screeching halt in your portfolio.

I took a look at a few publicly traded clunkers last week. I singled out stocks that I felt were giving shareholders crummy mileage. I then suggested related stocks with energy-efficient fundamentals for growth as replacement vehicles.

I have a few more trade-in suggestions, so let's head out to the Wall Street showroom.

Clunker: Microsoft (NASDAQ:MSFT)
There's a lot of love for the world's largest software company. Windows 7 is now two months away. The Xbox 360 is holding up better than its video game rivals. Bing is turning heads in search.

This may all be encouraging, but don't you have the sneaking suspicion that Mr. Softy has peaked? Microsoft's operating systems and even its Office-peppered productivity suites will become at best cheaper -- and at worst, less relevant -- as computing moves to the cloud. In a few years, it may not matter if your computer is powered by Vista 2012, Linux, Android, or whatever feline Apple (NASDAQ:AAPL) is up to. It will all be about logging on to the Web for most OS-agnostic users.

Microsoft's push into retail and its extension of another lifeline to its moribund Zune line also seem to be doomed decisions, if not simply ill-advised cases of Apple envy.

Replacement: Google (NASDAQ:GOOG)
Don't let the Bing buzz distract you. No one is even close to toppling Google for search supremacy.

Google's most recent quarter found the planet's online advertising leader growing revenue and widening margins, encouraging discovering during an economic maelstrom.

Google and Microsoft are flush with billions in the bank. They also happen to be trading at earnings multiples in the teens for fiscal 2010. Microsoft may be a bit cheaper, but Google is the one that will continue to grow at Microsoft's expense.

Clunker: eBay (NASDAQ:EBAY)
A few years ago, eBay's namesake site would have been a natural recessionary winner. The virtual garage-sale platform is perfect for thrifty shoppers. Percolating unemployment is a trigger for home-based web-preneurship. However, is no flea-market hotbed. How bizarre -- there's no bazaar! Through the first two quarters of 2009, marketplace revenue has shrunk 18% and 14% respectively over last year's already crummy numbers.

PayPal is a beast, but the faster-growing Skype is being spun off. The end result is that analysts see earnings shrinking at eBay this year. They see marginal improvement in 2010, but the projected profits are still short of last year's rather mundane bottom line.

Replacement: MercadoLibre (NASDAQ:MELI)
If you miss the hottie that eBay used to be, you can dig through old yearbooks or just warm up to MercadoLibre instead. Latin America's leading e-commerce exchange is the speedster eBay used to be in the 1990s. In its latest quarter, revenue climbed 42% in local currency levels, with earnings exploding 127% higher.

MercadoLibre also has its own mini-PayPal in MercadoPago.

On a valuation basis, MercadoLibre is considerably more expensive than eBay. However, if you ask any of the lucky shareholders who made a killing on eBay shares in the late 1990s, paying a premium for growth paid off until the wheels came off. Until MercadoLibre stops growing, it's the ride for you.

Clunker: Pulte Homes (NYSE:PHM)
Pulte is making lemonade out of lemons with last week's successful acquisition of homebuilder rival Centex. I'm not falling for the "Welcome" floor mat.

It's true that new home construction has risen for five consecutive months, but this only takes us back to October's levels -- when Pulte was trading for roughly half as much as it is today.

There is still a glut of existing homes on the market, and analysts see Pulte at least two years away from a potential return to profitability. Why overbid early?

Replacement: E-House (NYSE:EJ)
The best thing about living in a global marketplace is that investors don't have to settle for stateside solutions. China's economy has already bounced back from the recession, and it's already reflecting in the buoyant real estate market.

E-House is China's leading real estate agency. Earlier this month, E-House delivered a 48% spurt on the top line for the second quarter, with earnings growing even faster at 68%. E-House's guidance for the current quarter calls for accelerating revenue growth.

You don't have to pay a king's ransom for E-House. The fast-growing company is trading at just 16 times next year's net income. You can speculate on what year domestic developers will recover, or you can cash in on the Chinese revolution that is taking place right now.

Do you have any other "clunker vs. replacement" suggestions? Share your picks and pans in the comment box below.

Google and MercadoLibre are Motley Fool Rule Breakers recommendations. Apple and eBay are Motley Fool Stock Advisor picks. Microsoft is a Motley Fool Inside Value selection. Kick the tires of any of our Foolish newsletter services, free for 30 days.

Longtime Fool contributor Rick Munarriz is not afraid of trade-in values. The road ahead is too promising to live in the past. He does not own shares in any of the stocks in this column. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.