Here's an instant hack for awesome indie cred. All you need is a car seat belt, scissors, a lighter, and something to sew with.
Step 1: Scraptastic.
I picked up this burgandy loverestraint at an auto scrap yard for five bucks. I trimmed the ends with scissors, and used a lighter to melt the ends so they wouldn't fray.
Step 2: Size at your leisure
I decided to leave on some extra length in the belt so that I could take the stitches out and resize it if I wanted later. I measured the belt around my waist, and marked a line on the longer strap where it overlapped with the shorter. I folded over the extra, and sewed it onto the other strap, then folded over the little tail that remained, and put a line of stitches into it.
Step 3: Finishing
After sewing and checking the fit I was pretty much done, however I found the metal tab was a little too wide to fit through most belt loops. I carved the corners down on a sander (a file or jewelers saw would work as well) so it would fit easier.
Step 4: Done.
Well, that's it. I'm done. I might make the belt adjustable sometime, but I don't really plan on expanding my waistline in the near future. Now it's time to lay back, and revel in the warm embrace of the family van.