Roblox already does a lot of work in the background to ensure stuff looks smooth for all clients, so it’s probably best to stray away from doing your own thing here. Setting the network ownership of the vehicle to whoever is sitting in it should be fine here (in fact, I think the engine does this for you already).
There’s not much in ways of replication tools available to you when it comes to creating stuff that everyone except the driver can see. Something will be choppy, especially if you have multiple people sitting in the same vehicle.