Well, when I switched insurance policies there was a section on there for aftermarket parts, I added my exhaust, intake, etc etc etc and rims...the only thing that they added to my policy were my rims--I don't think they will hassle you for the aftermarket parts, if you pay the deductable they should fix it back to the same condition. I freaked when someone wrecked into me big time, I sent the body shop a list of all my mods (hehe down to the brake pads) and said that I do not want the OEM parts back on there if that is what they had to do, he said they would put the same parts back on that were on there when I had the wreck ie/if he was going to replace the tires he would have to replace them w/ the toyos and not the potenzas.... I don't know if they require a police report or not. I would def. have them come out and look at it (the ins. co.) and see what they say after assessing the damage....
Good luck man, I feel your pain......