How exactly do you get air suspension

It is an ultra rare drop that has a bigger chance to drop from premium shipment.

You can get Premium Packs on two ways 1st buying Speed Points OR during gameplay second takes some time.

I got mine air suspension from a normal pack though. And some luck indeed.

But since this is basically hydraulics, its pretty much OK that the drop is rare. If you think back to NFSU2, full-scale hydraulics upgrade was extremely late game.

Well I just got mine, Level 15 reward, base shipment.