I say buy a car direct from the owner instead of dealers which you can find it here in QL Classifieds column.
Get the car check at any service centre if you have doubt about the condition, accident history etc. at Salwa Road.
Regarding the cars selling at Salwa Road has major problem, well its depends on how you view the car and select the right one. Most of the cars selling at Salwa Road are too expensive and you will get rip if you not sure about the market value, so pls beware. Thats my personal opinion. Cheers mate