There are a lot of vehicle types and categories in Grand Theft Auto, so it makes sense to have mod shops to accommodate them. Los Santos Customs is the most popular shop in the game. You can modify the majority of vehicles in the game except for the ones you get from Pegasus.  There are other custom Shops like Benny’s Original Motor Works where you can tweak certain vehicles like lowriders, and even upgrade a standard model to its high-performance variant. Take the 900R and Elegy Retro Custom.