My 350z is my second car so is parked up on the drive for days at a time.
I have a telescopic steel bollard at the end of the drive, put up nightly, dislok and a small wheel clamp. If someone is hell bent on steeling a car, it's gone but you can't make it easy for them. Visual deterrent is your best bet, indicating time, effortot and a lot of noise have it away.