Does anybody know where I can get a set of the rubber seals grommets that go on the roof rack or luggage rack?

junk yard

Went to the junk yard but all of them are pretty hard and fall apart when taking them out.

just go t a local parts store and pick up some that fit

Check the dealership.

McMaster-Carr has some rubber well nuts, but not in metric thread

Later XJs came with metal rivet nuts. I replaced a couple of missing rivnuts with dealer parts ($6 each), then later bought a bag of 6mm from McMaster and replaced them all with new. The ones from McMaster are a little large outer diameter and you have to drill the hole a bit, but they work alright.

Renix has the metal rivet nuts also. Btw my leak turned out to be cracks in the unibody outside of the hatch hinges. The little "drip rail" was feeding water right to the crack.

Going to try the parts store see if they have any.

Ace hardware. They're called "well nuts".

well, nuts. Never installed one. I guess they expand in a clean hole and make a metal to metal seal.

Nope. Expand and make a rubber to metal seal.

http://www.bestblanks.com/signframes...CbT7w_wcB#2353

A well nut is like a rivnut except its mostly rubber instead of all metal. The nice thing is its not as harsh, and is removable just by releasing the tension. I use them to hold the center console pieces to the floor where rivnuts are not flexible, and also use them to hold 6x9 speakers to the fiberglass hatch where rivnuts would be hard to install without damaging the fiberglass.

Sheez...live and learn. Chasing a leak on my Brown 90 I'd almost swear they were metal, but I just looked, I didn't scratch around with a dental pick or something.

OK, I see it now, it just looks like metal...but has rubber. The second photo is where my leak turned out to be.

Actually they are pretty easy to install into the fiberglass imo. I re glassed the hatch drilled 8 new holes for my aurora bracket installed the rivnut and was haven't had any problems in the past 4 years.
It's all depends on the type of rivnit your using and your puller. I used the one that is sold at hf but the down side they don't sell the rivnuts by themselves anymore, you have to call and order them.

mcmaster.com has a large selection, its where I buy all my odd hardware