uh oh, spaghetti oh's . Does it have a boost controller?
The only other person to drive my car, in a year and a half of ownage, is my dad when I was on Holiday for 2 weeks. I think people only appreciate these cars if they have put the hard earned money and time into them, if not then they'll fk'em up!
Make your mate pay for it, a decent mate would fess up and offer to pay.