in response to the C3 question
How do I install 78-82 rear door glass weatherstrips

Although I owned a 1979 when it was new, I did not keep it long enough for the original weatherstrips to need replacement. (The T-tops would leak around the left front drivers corner and right front passengers corner in moderate to heavy rain at speed. I often tell people: That's factory.)

The following is based upon the information in a 1979 reprinted factory Assembly Instruction manual. On sheet 24 of section C01 to C12 is an illustration showing an exploded view of the assembly. You will need the following: pop rivet gun, 7/32" drill and smaller drill bits, adhesive and cleaner.

Note that there were three 7/32 diameter holes drilled in each "B" pillar with very precise locations. They were probably actually located with a template, and their actual locations were dependent upon accuracy of the assembly line worker. You will need to remove the interior "B" pillar trim to expose these locations. Then the original rivets must be drilled out. Use care and precision to avoid enlarging the holes. Start with a small drill bit.

Remove the old weatherstrips and clean up the old adhesive. Test fit the weatherstrips to the body. Examine them and compare the indent locations with the holes in the pillar. They should be reasonably near each other, otherwise you will need to relocate them in the pillar.

After test fitting, apply sufficient adhesive. Next mount the rivets from the inside. Push the rivet completely into the "B" pillar while applying slight pressure from the outside to hold the weatherstrips. Squeeze your pop-rivets gun to set the rivet. Clean up excess adhesive and close the doors to put pressure on the weatherstrips. Note that the new weatherstrips may make the rear glass bow out until it settles. At the factory they would adjust the door glass if the fit was not satisfactory or if it failed the water spray test.