This sounds like money in the bank!!!

Insurance regs allow you to collect the cash instead of repair

Getting written, sky-high dealership estimate is good first step... but be forwarned that insurance company can also get its own estimates of repair - and if dispute arises, then court will award estimated damages based on average of at least 3 repair shop written estimates.

The car??? dont worry about it..... black soot could have been mufler dust... If oil system was disturbed it would show up on guages..... But you sure as hell better be checkin the oil and watching the guages.

Otherwise as you've said - you can bang out the trunkwell with a hammer yourself...... do the same thing to the oil pan - it wont mind.

But dont repair the car youself until cash arrives from insurance..... that means no spray paint, no nothing.

With luck you can score $1500 for complete mufler, new oil pan and trunkwell dent.... taaake the cash!