Just Bought a Pre Owned Car for 17k 30 Days Ago Now Its Worth 10k? Possible?

I purchased a 2005 acura tsx 60k miles with nav about 30 days ago from curry acura westchester. Sales manager told me kelly book price was about $18500 so i figured $16,999 was a good price. 2 days after purchase i saw another car i was interested and went back to see if i could trade it in for the other car and they told me i must wait for title. I just recieved the title the other day and was browsing cars and was curious i put in trade in value and price comes up 10k is it possible value of car can go down %50 in 30days and if so is that legal??? car is in same condition as when i bought it. I only made one payment so far, put down $10,000 car was $16999. Please somebody this cant be what should i do??

Suggestion:

The trade in value is drastically lower than the blue book retail value. I once bought a car at 13,000 dollars and 2 months later attempted to trade it in, and they only wanted to give me 7,000 for it so as bad as that sucked and as shocked as I was, this horrible trade offer is reasonable and standard. It doesnt matter that you only had it for 30 days….. If you try to trade it in be it the same dealer or different dealer they will very most likely offer you at or below trade value… even if its only 60 per cent of what youve paid for it. Unless you have the means and patience to try and sell it on your own, which requires title ownership and other details, you're screwed. your only hope is if there is a legal clause in your juristiction or in the dealer policy that allows you to "return" the car within a 30 or 60 day window, but such an option is rare. Your only option is to drive the car for several years then when you go and trade it in the impact you will be hit with on money loss will be much softer and you will have gotten years of use out of it. You could buy a car for 20,000 dollars, turn around and trade it in to the very same dealer the next day and they might offer you only 13,000 and you just ate 7000 in 24 hours. This is why buying a car requires you to do much thinking, homework and research or else if you become unsatisfied for personal reasons only, you're exposed.