mustang vs infiniti which should i chose?

Mustangs suck dude, stick with the infinity for sure.

If u don't mind having having a 90's car, I guess it seems like a good deal. I can't think of any negatives

The thing about Mustangs is that they are a lot of fun to drive and get looks when you drive by simply because it is a Mustang. I am a Ford fan, so I am a little biased, but Mustangs have that American sports car roar to them, especially with a few modifications and if you're willing to drop a few bucks on a new exhaust (which it already has). I have a Mustang for a daily driver, and while it is not always the most comfortable car to drive, if you're looking for a fun car to drive the Mustang is a great option. The Infiniti is most likely the more comfortable and efficient car to drive, but I would definitely suggest the Mustang will be more fun especially with the modifications you listed.

I would keep the Infiniti. No doubt about it. The mustang GT uses premium gas and with no modification will normally destroy your bank account with its factor very low mpg. Also, reliability suffers a lot with those modifications. I understand that you want something faster, Finally, you should consider why is the owner REALLY selling the car. It may be that the car sucks or that it cost too much to use it everyday.

If you want a weekend ca it would make sense, but no as for daily use.