I hate modern cars...

I blew my Breeze radiator on the way home from work this evening. My heater was blowing cold air all the way home and my temp was creeping higher than usual but it wasnt close to hot (because there was no water to the sender most likely) so I get it home to find that I had a hissing from the upper radiator bung, losing all my coolant. I vent the cap under about 6 rags and it is screaming hot so I let it cool over dinner and fill it with 4 32 oz big gulps of water and I see the water is leaking from the radiator bung. I get my clamp pliers in there to R/R the hose clamp and the frigging bung comes off inside the hose! Damn thing is made of plastic! So I got about 1/2 of the spud still intact but its cracked around 1/4 of the base so I put some JB on it, hose and a screw clamp on what is left of the bung and will let it set overnight. Hopefully itll survive the trip to the wrecking yard for another plastic (cough) radiator. Should I Keep the cap vented so it doesnt build pressure? It just needs to last about a 15 minute drive. I figure I can pull a radiator in about 15 minutes, 4 bolts on the cover, 4 on the condensor and cut rubber hoses with pocket knife. Plastic radiator tanks, WEAK!