Car "Upgrade Packages"

Going forward what I would do with car rarity is make cars obtainable in a variety of ways. One of these ways isn’t only a cool way to get a car, but is actually pretty realistic too.

There’s several “aftermarket” brands that, for a price, will completely upgrade and revamp your car. A notable example is RTR and their Mustang upgrade packages.

What if the RTR Mustang was only obtainable by first owning the 2018 Mustang GT, going into the upgrade menu, and paying credits to have the car modified into the RTR Mustang? This process would replace the car completely and would be irreversible.

I think this is a pretty neat mechanic and would love to see it in a future game.