Trying to repair the rear folding glass on my 1967 Firebird. The silicone bead that holds both glass together has come apart. I removed all the old silicone bead and prepped it to run another new bead, but not sure which product to use since it needs to have extra strength and flexibility. I tried the regular clear silicone for windows , but as soon as I lowered the top the bead cracked not strong enough. Was told that it has to be a 400 % flexibility sealant like a Tec7 Sealant that is only sold in the UK . Not sure if there anything similar to that here in the US. Has anyone performed this repair and can advise which silicone sealant could work … I’ve included pics of the the repair and prep work , just holding off to find the right product to use. Or has anyone repaired this using another method . Thank you all..