Keep up on routine maintenance.
I have owned my infinity for 8 years. Problems: mechanically, none. The back door motor broke and is very cost prohibited to fix. Performance: excellent. Reliability: always reliable, never have to worry about being stranded. Comfort: top notch! A good vehicle to take on a long road trip. Features: backup camera is great and easy to see behind you verses others that I have seen. Lots of storage. I think the most important thing to remember if you are buying an infinity is that if you keep up on routine maintenance, your car will last.