b8 S4 vs G37x vs GS350 vs random

I have this going one another forum and thought I would bring this to a more universal sight too.

I will be purchasing a car in the near future and I am going for CPO. I really want an AWD, so the S4 is my first choice. I heard the Quattro is sick. The car will mostly be used for Road trips and Weekend driving. I have a older Nissan Maxima that is my daily driver. My main issue with the Audi is that most people state that it will be costly and frequent, in the future, and I plan on keeping the car for a long time. My 96 Maxima currently has 171k on it.

I live in San Antonio Tx and it can get pretty hot. Are there any reasons I should avoid the Audi besides costly repairs??? I am not a wrencher, but I am not afraid to dig in.

I am open to other cars too

Please give me suggestions!!!

So far the cars that caught my eyes are:

Infiniti G37x (looks cheap in most areas, but still a great ride)

Lexus GS350 (Never owned a Toyota and this one seems pretty nice)

Audi B8 S4 (so far has all the specs I want and I like to have cars I don't see on the road all the time)

***BMW 335xi is not on my radar because I see way too many BMW's out here. I don't want to join the club.***

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Subaru Impreza or Lancer Evo are interesting too, but I'm looking for a little more luxury