That thought had occurred to me.
After being excited to the point of silliness when the game first came out, I never finished it. I'm just getting back into GT5 and I'm currently saving for the Ferrari P4 which is why I don't want to shell out a couple hundred thousand credits for the Gallardo which I don't want, would never drive, but only need it to advance through the game.
The only Lambo I was interested in is the Miura. (The Diablo, Chrome Line Murcielago are languishing in my garage, having never been driven)
I just recently purchased the Miura and depleted my credits. But hey, I got a nifty "penniless" trophy in addition to a nice classic!