Haven't posted in many years... (although posted quite a bit back in GT4 days), and just playing GT6 for first time...
I really wanted to mention to *someone* that it's possible to beat the Toyota 7 and Chaparrals at monaco in a freaking Honda Civic '79 max tuned and set up perfectly just for monaco (I imagine there is zero chance at Apricot Hill or Silverstone!).
Easily the hardest race in any GT game I've actually won.
After reading this ancient thread, no wonder I found it hard!
Saved the replay at least.

Regarding thread topic... the Civic '79 may be technically the cheapest car you can win at least the monaco race with?... not so cheap with the mandatory nos tank however!