nice one,is your bumper repairable or totalled?
Well i suppose its salvageable really,but its a bit weak on the one corner now where it creased,but the good thing is,that i can repair all the car myself,and have access to my mates bodyshop. 
My advice is to have a word with a laminator.
To illustrate - the rear LC bumper on my Carlton was from a burned out LC, so the bumper didn't fit properly as it was bent and twisted - quite badly as it goes.
Luckily, father outlaw worked at Lotus as a laminator and toolmaker, said to take it down and he'd sort it.
He cut it into sections and then used some sheet steel to screw them back together (on a flat floor) so the bumper was right.
Re-laminated it, then removed the steel plates.
Filler, primer, job's a good un!
Bodyshop guy thought I'd bought a new bumper!

Where you bumper is weak, it can be strengthened

Hope you get it sorted, and this little tale helps.
