I want to mount this on my front seats so I'll definitely want the non-drilled holes. Many conversions have swivels on the front seats (after all, they're probably the most comfortable in the vehicle) but I want one that slides into the back. It doesn't have to do more than support its own weight back there and it's back over the base while driving so this should do the trick!
I really like the notion of using a bar to attach the L-Track to the van. If you were to do the project again, with the likely (low) weight supported by the L-Track, would you have used aluminum bar instead of steel? I'm thinking of ease of fabrication and weight savings would make aluminum a good choice here.
Great vid! I definitely want to do the same thing for my sprinter. Do you have a video on how you removed the headliner? Is it something easily removed and put back on? Thx!