Uhhh.... it has a VACUUM line, so under heavy VACUUM it should shut (ie. in gear during deceleration....) which means you can't see it shutting at idle or when the car is off. I think it's to help prevent afterburn or something.
You'd have to strap a camera to the bumper and then drive it up to 25mph in 1st gear, then let off the gas while leaving it still in gear, then review your footage
