I don't know about the "out of warranty" = madness.
Our 2004 X3 has been very good, post-warranty expiration. Of course, we had a lot of warranty work done on that car (steering rack, seat mat, accelerator pedal, window regulator, 2 sunroof cassettes. Of course, we only have 48,000 miles on the SUV but it's still a data point.
My 2003.5 M3 vert with SMG has also been very good, post-warranty expiration. Since the warranty expired, I have only had to have the passenger window regulator replaced. If you have the time and inclination, it a DIY but I had the dealership handle the replacement. Again, my experience may reflect low mileage as I only have 20,000 on that car.
There's a thread on e46fantics were SMG owners are posting up their experiences (good and bad) so that a more comprehensive sense of frequency of SMG issues can be assessed. It's worth a look.
2004 e83 3.0, 2003.5 e46 M3 Cic, 2008 e9x 335xia, 2008 Sienna XLE Limted AWD
Gone: 2006 B7 A4, 2003 Honda Pilot EX-L RES