Sounds for vehicles shouldn't be a problem because Gytyyhgfffff already found out how to do it better than the methods I've used before. I got car sounds for days, from realistic to cartoony, so it's just up to him to release that and show us how to use it. Minor sounds like impact sounds and explosion sounds, as well as spawn sounds, are all do-able already, it's just nobody wants to change them.
I think we need more vehicles like the one Teneksi's working on. The amount of features on that vehicle are truly innovative and, in combination with other mods, could surely bring things to the table we've never seen before. For example, using the trunk in combination with the inventory mod.