I don't really belong in this forum, since I don't own a Colorado... (got a Chevy V8 though)
...but someone linked me to this thread and I had to comment.
I'm hoping more people will build these doors, because I think they're cool and there's too many lambo doors out there. Also if more people build them it will help me work out the little kinks I have in mine. So regarding the doors being flimsy... in the video they're extremely flimsy! On my second attempt, I thought it was necessary for the front "locater bar" to tuck inside the door, so I cut the inner bottom of the door out. This made the door flop and wiggle like crazy. It turns out the bar doesn't have to hide inside but the damage was done and I hadn't yet fixed the hole I made when I recorded the video.
Peace out. Thanks for the kind words people!
Mankandie
Las Vegas
P.S. I'm down to see the van track system, but you'd likely have to unibody the truck and hide the track somehow at the top of the bed rail. A track in the bedside would be a bummer.