you can get the SA to bring you go see the particular car before registering the car with JPJ.... do the inspection then.... if you are satisfied, place the downpayment and sign the docs for registering.... if you are not, then get the SA to bring in another car.... thats what i did...
normally the defects are quite small and can be rectified easily.... but things like the rusted seats being rectified before hand, i dont know..... all i did was to lodge the complain when i placed the downpayment to make the claim faster...
btw, possible, you can see their inventory with the VIN of the car, hopefully they would have more than one car with the choice you are looking for....