This is meant for car changes to show up on existing career when installing/removing car dealer mods. Steam Community

If you are playing an older or abandonware version of the game (like the famous v2.2.1 MWM or LE2MWM builds), you will need to download the mods manually: Search trusted community archives like archives for "SLRR 240SX".

: Players frequently report that the game is unstable and prone to crashes.