I can relate to that.. I was driving my mates manual VS Commonwhore in the wet around a roundabout with a full carload of people.. The car had $400 tyres on each corner.. I was doing about 30km/h, gave the accelerator the gentlest nudge as I was leaving the turn, and suddenly I'm at a 45 degree angle heading straight for a right angled curb!! I backed off and after fishtailing a bit I reeled it back in.. But it scared the absolute shit out of me!! No warning whatsoever!!
Compare that to another mates VT, when he plants it around a corner the inside wheel lights up and the rear end of the car barely moves at all!
Really sorry to hear about your car man, but at the end of the day you should both be thankful that you werent hurt!! You can wreck the car, regain some cash and your girlfriend seems to be willing to help you out. You'd be surprised how quickly you can accomplish things when you set your mind to it so don't be too down hearted!!