I have had my 2005 350Z Roadster for 9 years now and the only things that have gone 'wrong' were rear discs needing replacing (my own fault - should have checked pads) and a screen washer pump that gave up the ghost.
However, the 2012 Audi A5 1.8 TFSI Coupe is turning out to be a nightmare. We have only had it for about 4 years (under 70,000 miles when bought) but have had to replace: both rear shock absorbers, air con 02 sensor, cooling system expansion tank, drivers door lock, boot lock and now, to add insult to injury it would appear that the cam timing sensor is playing up, my boot will not open and I am getting constant 'stop/start' not working, n/s reversing light u/s (it is !) n/s rear fog light u/s (it is !), n/s side light u/s (it is !) - boot not opening, bulb failures (?) and stop/start failures are down, apparently, to a well known n/s rear wiring loom or ecu issue due to water getting into the boot. My garage tell me that it is a widespread issue across Audi, VW and Skoda.
We have been offered a 2002 Maserati by my daughters partner and I am sorely tempted despite it's age. I will never touch an Audi again !!