I am also with just car and am In the motor trade, when you obtained your policy they would have given you a payout figure which is what you get if your car is stolen not recovered or written off
If you added mods to your policy they would have adjusted your payout figure to include such items.mine atm is covered for 16500 agreed value without all the mods (only exhaust is on the policy), have to ring up and add the cooler, rims, gtr interior, aftermarket computer (power fc), coil overs, all the "pretty" nismo gadgets ie; fuel cap, oil cap, the momo wheel and all the other shyte. just car should be very helpful with ne of that, best advice I can giv to neone is that if your in an accident that is not your fault call the police straight away and have them investigate as their reports are bible to the insurance companies this way it also deters assholes from coming back with bullshit evidence to try and screw you over at it is too costly to go through teh court systems these day and the risk of being done for fraud