" I figured the next time I parked at my girlfriend's place overnight I would have to buy some crackpipes and tape them to my bike as a peace offering. Overall, I wasn't that upset "
Those aren't vindictive. If you want vindictive, do what I'd do.
Discreetly wire a continuity circuit around the tops of the spark plugs. When the crackhead proceeds to saw through them, he or she would break the circuit, and by doing so, activate the five-pound block of C4 I would have situated in the gas tank.