When I drive (which is a lot less than I bike), I drive a stick, and at least at reds, I put the car in neutral and engage the parking brake so I can rest my feet, which (except for the loss of momentum) is comparable to the trouble incurred in dismounting for a bike.

In general, driving or biking, I think we should stop trying to decrease effort, and increase it instead. It's good for you. As a cyclist you get stronger, faster, more skilled. As a driver, you get more skilled and are forced to stay more alert. All of these things make you and everyone around you safer, so savor and put as much of yourself as possible into your cycling and driving, for everyone's sake. You don't get good at things you don't do.