Everybody is always posting on here about peds getting stolen... At the Home Depot, you can buy a motion sensitive alarm that is used on sliding glass doors. It detects the vibrations of someone trying to break in... not that little magnet thing. These things are SO sensitive. The brand is doberman (link below).
You could totally stick this under your seat and turn it on at night or whatever. I have one, and it's so freaking loud, if it didn't scare the thief away, you'd know to get the hell outside with a bat. Ten bucks, battery operated, installation is a joke and why the hell not anyway??? You spend hundreds of dollars and tens of hours working on your ped, why not do all you can to protect it!!! Good if you aren't able or are too lazy to lock it up... The links on MA never work anymore so just copy and paste the URL.