I think it doesn't have to be insecurity. I drive a Hyundai Kona, and have no particular desire for speed or performance; I'm happy for other people to have sporty, fast cars even if they are modded, but I do get annoyed by very loud vehicles (regardless of performance; e.g. small motorcycles or pickups that are very loud are also annoying).

I'm not blaming OP specifically for this, but I don't think you have to drive a sports car to be allowed to be annoyed by loud cars without it being 'insecurity'.