11 minutes? Have you used a "tuned" Fiat 500?
Get a detuned race car (take a look at the leaderboard for good ones) and you should win it easily.
I tried a new Fairlady Z (Z34) '08. Up'ed the HP as much as possible and lowered the weight. Still didn't stand a chance.
Honestly, I never even thought about down tuning a car. The 908 that several people have mentioned is 4 million dollars new and I don't have anywhere near the money needed to buy something like that. I do have a couple of race cars tho' and I'm going to look at down tuning one of those. That certainly seems to be the option of choice for most of those that have replied. I'll report back with results.