Summary

This roof rack will cost you < $50 total and a few hours time.

Instructions

I have yet to print/install these on my car.
This is how I plan to do it:
Buy 1" X 1" X 48" T-Slot from amazon
Buy cold galvanizer spray
Buy skateboard shock pads.

Use an exacto knife to cut the pads to the shape of the base of the holders.

Dry fit/mark drill holes on roof
Drill holes and spray with the galvanizer
Use rubber washers and stainless sheet metal screws to go through the base into the roof.

Put some epoxy over the screw heads.

I plan to use a combination of epoxy and screws to permanently bond the T-Slot to the 3d printed mounts.

I will post my results/photos of the finished product, as well as whether it passes the leak test.

Comments are encouraged. I really dont know what I am doing. I looked at how professionals install roof racks on gutterless vehicles. If you know more than me please help : )

DIY T-Slot car roof racks