Does anyone know if the hardtop on 1980-1996 Ford Broncos cracks under the "rigors of prerunning" ? Here's what I'm wondering... has anyone reinforced the factory hardtop with another layer of glass and resin? I gently set a spare tire up on the hardtop the other day when the Bronco was in the garage and noticed the roof REALLY flexed under the load. The tire/wheel probably weighed no more than 70 lbs. Any ideas on beefing up the roof? I was thinking it'd be nice if I could toss a couple lawn chairs up there to use for spectating. Adding up to another 50lbs of additional glass and resin to the stock roof would be AOK with me - think that's enough?