在dealer买到有问题的车怎么办？

There are many experienced chinese here can help you.
Please post more details .
1)Which year, what model you bought ? How do you know there is a transmission problem ?
2)Based on what you bought,  Chevy with $150K miles may have more problem than you expect/or can handle.
3)I assume you haggled for the price of the car. If so, trade with Chevy as "equal value" defined by dealer may be a very bad deal for you.
The Chey Aveo listed at the dealer's website for $5k. I will put it at $2k. I am sure an experienced buyer can go in and get it for less than $2500.
4)Obviously, you have no experience in buying used car or deal with dealer, I suggest you to ask a American coworker negotiate with the dealer for you. I have seen good result (fix for free).

yep,I havo not choices.i can't get my refund back, I can't ask them fix my car,and all I can do just to hope the blue car is better than last one. I know your advice is very helpful,but I don't have other choices.i have to deal with them by myself. I feel very hopefulness . First time to deal with a dealer,and also first time got trick by a dealer. Sigh.