damn thieves! Usually us car guys we just take a step back and go "wow nice setup!". and take a peek inside and slowly walk away.

 

get a custom car cover......

I'm looking into one myself and it will accomodate any shape or size car.

 

A car cover to put over it when I am parked? I can see it working, but I can see it getting stolen too ;p

Plus, how hard are these things to put on and take off?

 

You can get covers that lock under the carriage of the car with a bike lock kind of chain / cable. A friend of mine had one for his celica. Sure people can cut the chain, but most people would not think it to be worth the effort. The cable also prevents people from taking a peek inside the car to see if anything is worth stealing.