Upgrade and Modify cars (see desc)

[TJ the HedgeScout]

Yes i know there is Car Modification Shop which i am using, but some of the upgrades do not work properly sadly. The tire upgrade do stay, but stuff like Engine, ECU, Suspension, and Brakes are weird where sometimes it doesn't keep the upgrade or it regresses the changes in performance but keep the upgrades regardless of their bonuses not working.
It would be nice if it would be incorporated into the game itself via update.
Granted i have it installed through vortex, i could "try" and use it manually, but i think this issue persisted even when i was originally installing my mods manually.