The worse car I ever owned was and Alpha it was fantasic when it was running right but it would always spoil the pleasure of the drive by doing something daft with the electrics, Best car I ever owned apart from my RR P38 was a Porsche 944 that was a real pleasure to drive but the wife hated it so it had to go I tried to get rid of the wife but that would have ended up costing a lot more money.
Good luck ROAf I'm sure you will enjoy your Audi until something goes bang, then it will be a toss up between writing it off or fixing it because they are expensive beasts to repair and maintain.
Oh and the bit about the LPG conversion, I had a Jeep Grand cherokee converted and it ruined that car because of the crap installation and once the guy got my money he did not really want to help. So this time I'm doing it myself like the old adage says "If you want some thing done right....".
Jim