Forza Horizon Car Tuning

I’ve been looking for a way to mod my cars in Forza but all i’m able to do (with diamond) is add credits, RP, add secret cars, eta… but although great it’s not what i’m looking for, i want to be able to fully customize key aspects of my car such as gear ratio, Grip, Camber, Engine Swaps, Horsepower, FWD-AWD-RWD conversions, weight, things like this. I’ve spent a solid 7 hours non stop looking all over the internet but all i can find is either not what i’m looking for our outdated versions of Horizon. If there’s some kind of tool already out their that’s up to date and actually works for this purpose please let me know. but if this even remotely possible and i’m in over my head somebody tell me so i don’t spend more time looking in vein.

Sent you a PM.