I wouldn't worry about it too much, wait a year or so and then sell it. Look at the MP3's, there's a sspecial model protege that originally sold for $18,000 MSRP or thereabouts, and now has a blue book trade in of $10,500 and a private party value a little over $12,000 for one in excellent condition with about 24,000 miles on the clock. For those who bought their MSP early on and paid much closer to MSRP than they are going for now, they'd be losing a lot of money if they wanted to get rid of it, but for anyone buying one now for $16k-$17k, I'd say depreciation over the next few years is not going to be horrible.
You lose a lot of money on a first year trade-in no matter what, the only way to come close to breaking even is with a private party sale. I've been in your boat before, I sold a WRX wagon after only four months but because it was a private sale and I found a reasonable buyer I didn't get hurt too much on it. If you really want to get rid of it now, advertise it on autotrader.com or in your local paper. If you don't want to deal with it and you'd rather trade it in to a dealer, you're going to have to wait a while.
Maybe try carmax, they'll buy your car from you, and I've heard a few people have had reasonable results with them (better than dealer trade-in) but I doubt it's going to be anywhere near what you're expecting to get for it.
Here's something else to consider - if you're getting a new car at invoice, you're probably going to get financed for the MSRP of the car, if not about 10% more. If the amount you're upside down on your loan is less than the difference between invoice and MSRP on the car you're looking at, you can usually roll that into your new loan. It hurts you in the long run, but if you absolutely have to get out of the car you're driving, that's one way to do it.
