I have just sold a 23 yr old gt4 st185. It was highly modified and had a few subtle changes to its original appearance i.e. more stealthy. I sold it for quite a lot more than most would sell for. How was that possible? Because it was a rot free, genuinely nice car. If you have a nice car from any make, you'll get a good price for it. There will always be someone who'll give you just about what you want for it if it's a nice example irrespective of the market value according to what they go on Ebay for, or Autotrader.