Haha good man! Looking forward to comparing differences since the Z4M has a different exhaust configuration next-next meet for sure then
M3 update.
My guy has stripped the rear down and given everything a good seeing to. He's also got a local specialist down the road to get a 2nd opinion. They have come to this diagnosis.
* The boot lid needs replacing as it is slightly bent. BMW did not mention this at all. Used bootlids aren't readily available, ones that are in questionable condition. Sourced a new lid from BMW with all trim bits and coverings for £300.
* The exhaust backbox is actually fine. Only one of the hanger bits were bent. BMW said a new backbox was needed... The £150 OEM exhaust I bought earlier is in better surface condition than mine though (expected as it's done half the mileage) so he's gonna swap them over and I can clean up mine and throw it on eBay for £100.
* 2x parking sensors are needed, all 4 of mine work but the centre 2 have been flattened on the inside due to the impact. Cheap enough to replace anyway so that's fine.
* New (used) bumper being delivered Thursday. It was a complete item with crash panel. £180.
The materials cost for paint, prep items and lacquer for the whole car comes to £1700.
So far the tally comes to £2520 inc the alloy refurbs and before labour is added. The car will need to be MOTd once the whole job is done. The repairs are even easier than BMW stated. A few question marks over BMW's choice of replacing the exhaust and not the boot lid though but otherwise the repair outcome is looking to be excellent.
I can look forward to installing the Eventuri next Thursday with a view of getting the remap done on Friday and having a few grand left in pocket from the whole ordeal.