I've gone through a few, fitted a 'workman' open coil now, on a DV style mount. Folds down when wanted or smacks anything heavy. It's quite heavy gauge stainless, but the open coil has enough give for trees and car park barriers.
For 27/28mhz, sorted a nice short 'dial-a-match', which is only just a little longer than a VHF 1/4 wave.
Both on the back panel each side of the door, and no problems with either.
Used to run 'on glass' ones which were brilliant, but the van body and XS heated screens have ruled them out now - bit of a pity coz I could tune one for Coastguard work on marine and the other for 2/70. If it was not for the heated screen, I'd have refitted one 'on glass' and switched the feed to each radio as required.