I have no problem with narrowboats being fitted with bowthrusters, as (a) it makes the owner feel smug and better, and ( it helps create jobs at bowthruster factories, and boatyards that fit and service them. But I do have a problem with them being used. If you know how to drive a narrow boat, you just don't need a bowthruster, except perhaps (and I hate to admit this) on the rare occasion that your bow gets stuck in mud when singlehanding a boat.
Does your car have power steering and servo brakes, surely there not needed.