Nice thread mate, i will try to keep it short and simple since you only want us to say one negative thing :

1) 1997 Saab 9000 cs
Chassie Flex, you can actually the car flexing !
Not reliable, cost us AUD $12k to maintane the car over 8 years

2) 2005 Mercedes E350 Elegence
Steering too light.
Buttons for the air con is a bit cheap.

3) 2006 Subaru Liberty 3.0R spec B wagon
Really need more low end torque
Auto gearbox goes mental sometimes
Uses more fuel than the Merc