Do you care enough?
if i were to release it i would have to rewrite most of it so it would be easier to maintain and fix bugs for and im not convinced the mod is useful enough or will be popular enough to warrant such effort. addtionally i would have to make a server sided mod for the thing so the server could tell the client which sounds to play for certain vehicles. engine sounds are at best a gimmick that you hear and are impressed by once before you don't care anymore and turn them off because they're honestly a little annoying
as for suburbia i nor the team are satisfied with how it plays right now and due to that i have completely lost interest in the project. no im not going to continue working on it despite this because i dont want to be making something i don't even like as a hobby, and i would also like to move onto other projects so i can improve and challenge myself as a programmer and game developer instead of working on something basic for another few months or even years.