used car problem

I recently (3 months ago) bought a used 97 mitsubishi 3000gt vr4 witk 20k miles on it, I bought it in virginia. I paid a lot for the car close to 30k and it came with a one year "bumper to bumper" warrenty. So anyway I noticed a rumbeling noise from the front left wheel a month or so after I bought it. It progressivly got worse so I brought the car in about a week ago. It turns out the suspension in the left front is heavily damaged, the estimate from the dealership where I bought the car from was $2500. They agreed to fix the rumbeling noise but said that I was on my own for the suspension damage. When I bought the car the salesman explained to me that there was a spot weld on the frame and that that car had run over something causing this very minor frame damage. Then when I brought it in for the rumbeling the mechanic was like this has been in an accident. So now that there is all this damage to the vehicle I am thinking that they knew about the suspension damage before they sold it to me, and didn't want to go through all the expense of fixing it when they can probaly sell it and pocket the money. I realize this may be very difficult to prove but I suspect it may be the case.
Basically what I am asking is there anything I can do? Sue them for the cost of the repairs?