I loved the old Gran Turismo (1 & 2) on the PlayStation.
I don't own a PS, and do not plan on getting one.

What I really enjoyed the most with GT, was buying some cheap car, then spend hours, days, weeks earning enough credits to buy upgrades, in the form of turbos, better tires, better brakes etc.
I loved pimping the same car for weeks.

Then I tried Forza for the Xbox360. It was quite similar to GT, but I felt I had a billions cars and a billion tracks/races. I was in a new car for every race. I missed the scenario from GT, where I had the same 2-4 cars that I had spent weeks on upgrading/pimping - and never needed more. I never felt a 'connection' to the billion cars I had in Forza, if that makes sense.

Is there anything for the PC currently that would offer a similar experience?

AFAIK, Project Cars and Assetto Corsa don't have car upgrades. They are more 'pure' and realistic (nothing wrong with that. I'm just looking for something slightly different)

I guess that only leaves Forza Horizon?

Any suggestions?

Cheers.

PS: Fuck M$ for charging almost twice as much for the PC versions of Forza, compared to the Xbox versions. Get fucked!