You don't have to lose your custom car. Use the in-game "Garage Export" feature (Ctrl + E while looking at the car). Load the 100% save, then use "Import Car" to bring your old build into the wealthy profile.
Sometimes, SLRR glitches. You might win a race, but the game fails to credit you the money or the reputation. In some cases, the game files become corrupted, and a player can lose hours of progress. Loading a 100% save game is often the quickest "fix" to get back into the driver's seat. Street legal racing redline 2.2.1 mwm 100 save game
version of 2.2.1 is known for being highly stable and mod-friendly compared to newer versions like 2.3.1. Installation Guide Backup Your Data You don't have to lose your custom car
The 2.2.1 MWM edition is a community favorite for its stability and massive mod support. A "100% save" typically provides: Sometimes, SLRR glitches