Best way to secure a van from being stolen?

[triangularmonkey]

Just had a special door step visit from my local family. They had great things to say about my van but unfortunately for them it is not for sale. Good reason to suspect they'll be back to try at a different time.

Parked on a driveway, any recommendations on how to secure it besides the obvious (taking the wheels off) right PITA as I need it as my daily driver. Most of the wheel locks look like cheap crap that comes off in 3 minutes with a grinder. Trackers are quite dear and I doubt they'd give it back lightly.