[Tannaton]

I had a XC70 which the previous owner had P*'d, had Aviva multicar and there was not change in premium when I told them.

However I've just found Aviva very awkward and uncompetitive at renewal time so I've got separate policies for my cars now and saved £300.

You should tell them it is "software optimisation" (which is what Volvo describes it as) rather than a performance tune. Strictly speaking, it is a factory optional extra (but retro fitted by the dealer like towbars)