GM does sell a roof rail option now, but I found it cheaper to buy my Thule hardware via amazon.
- Thule 460 Podium Foot Pack (also comes with end caps for the cross bars)
- Thule LB50 Roof Rack Load Bars (50-Inch, Set of 2), rated 165 lb load.
- Thule 3168 Podium Fit Kit for 460 & 460R Foot Pack
When assembling the fit kit to the foot, notice the steel rod running horizontally on the back of the foot. Hold this in place while attaching the fit kit's rubber foot.
Still holding that rod in place, insert the metal fit kit plate. Thread the two screws just enough so they don't fall out. Too tight and you won't be able to insert the cross bar.
Insert the cross bar. They are a bit snug, but push the end through. Do the same for the other foot. You will NOT be able to do this with the feet mounted to the car.
With both feet attached to the bar, carefully lower the foot furthest from you onto the Bolt EV rail, aligning with the rail mounting holes. Lower your side, pushing the foot as needed to fit within the rails.
Insert the security head screws (a bit of a PITA working blind, a mirror may help). Screw in using the provided T30 Torx wrench. I preferred using a T30 security bit in my long, slim Stanley ratcheting screwdriver. Easier to use and lest chance scratching the paint.
Measure the front crossbar overhang. From the foot bar clamp to the bar end should be 5-9/16".
Measure the rear crossbar overhang. From the foot bar clamp to the bar end should be 6-1/8".
I marked the bar with a silver Sharpie on both sides of the car so I'll have a way to rest the bars at the correct distance in the future if needed without measuring.
Pop on the bar end caps.
Now fully tighten the screws connecting the fit plate to the feet. This will lock the bars in the left to right position.
Pop on the Thule covers and lock in place. The plastic locks go in with the slit vertical, then press in and turn clockwise so the slit is horizontal. Test the cover. If it easy pulls off, rotate the locking pin 90° counterclockwise, pull it out, rotate 180°so the bottom of the vertical slit is now the top end of the slit. Try locking again.