I would talk to him when he's washing the 'Vette and say, "Nice car, is that a stick?" If it is - you've got your answer. Think about it. One foot on the gas, one on the clutch, on hand on the wheel, the other on the stick. Back out of the driveway - you're in reverse. When you need to pull forward, you engage the clutch and shift into first while using the steering wheel with the other hand. To continue accelerating, you need to shift into second, etc. You have no free hand to waive. Nothing sinister necessary. No need for your neighbor to be the stuck up snob when he's in the 'Vette and a great guy when he's in the truck (which makes no sense at all, really).

If you're familiar enough with stick's - you should actually be able to listen to the engine and watch the car respond as he pulls away and you'd know if it was a stick or not.

My suggestion wasn't just a joke, I was quite serious.

Heck, even if it isn't a stick - a Corvette doesn't steer as loosy-goosy as a truck. Minor inputs into the steering wheel have a more immediate impact in response from the vehicle. Not only that, but the consequences of making a driving error in a 'Vette are far more expensive than in a truck. Could be he's just not as comfortable taking a hand off the wheel until he reaches a more comfortable cruising speed.

I think the different driving styles is a much more reasonable answer. You would look quite silly approaching your neighbor and asking, "Why don't you ever waive when you're in the 'Vette?" He likely isn't even aware of it and will begin to wonder about the strange neighbor he has.

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Spock Jenkins of the Vulcan Jenkins'.