Tiger Seal, used on the Elise for virtually everything hidden and sticks like...... something to a blanket. It's rubber based so stays flexible, obviously waterproof and is extremely strong once set. Ideal for glass to metal bonds I'd have thought, it's currently holding the headlamps in place on my Elise and only there because the old units had corroded and I had to cut out the old Tiger Seal that Lotus used.
There's something very similar from Screwfix, a polyurethane building adhesive, or you can get the Lotus Appoved Tiger seal from Amazon. I honestly wouldn't use JB weld, it's going to set rock hard and I think with glass a bit of flexibility is better.
Brian