Here's why $3500 might be too much, considering the potential issue:
* Transmission Problems: The most likely culprit is a problem within the automatic transmission itself. This could range from worn-out internal components (like clutches, bands, or solenoids) to a more serious issue with the transmission case or valve body. Repairs can easily run into thousands of dollars, potentially exceeding the value of the car.
* Other Drivetrain Issues: While less likely, the clunking could also be related to the driveshaft, differential, or other components in the drivetrain. These repairs can also be costly.
* Hidden Problems: A "flawless" exterior doesn't guarantee a problem-free drivetrain. The seller might be unaware of the extent of the issue.
Before you buy:
* Get a pre-purchase inspection: This is absolutely crucial. Take the car to a qualified mechanic specializing in older Cadillacs or transmissions. Have them thoroughly inspect the transmission and drivetrain. This cost is a small price to pay compared to the potential repair bill.
* Test drive thoroughly: Pay close attention to the shifting behavior, especially after the car has warmed up. Note the severity and frequency of the clunking. Listen for any other unusual noises.
* Negotiate: Given the potential transmission problem, you should significantly lower your offer. Considering the potential repair costs, $3500 is risky without knowing the true extent of the damage. Aim for a price that reflects the potential repair costs or even consider walking away.
In short, while the car might look great, the clunking sound is a major red flag. Don't buy it without a professional inspection, and significantly reduce your offer to account for potential repair costs. It's very possible that the repair costs will exceed the value of the vehicle.