This was my first attempt at modeling anything, YMMV some fitment/sanding may be needed.

https://www.thingiverse.com/thing:3919513

 

I have a printer and a sunroof apart right now, I will print tomorrow and test fit in to the rail.

 

In the meantime, I fashioned four up using not a nylon nut, but bolt instead. It was way easier to work on with it screwed down into a block of wood, and the thickness was exact. The thickness of the nylon nuts at Home Depot were too think compared to the OG sunroof bushing. Installed them and the sunroofs work perfectly.

I did have to enlarge the hole a wee bit after the last photo was taken.

 

Hello Sandman,
It's been a few years since you posted this note, but I'm wondering if you are still making these sunroof bushings? Thanks. RJ

 

Were you able to get these working?
It would be a great part to add to your new store!!
As you know, there are a number of such little parts that make a huge difference, but most people don't have a 3D printer to make them. Having them on your store would be a huge plus.