I suppose I'm qualified to add my bit to this post. I had this 'S8' for 3 years. Underneath it's a 3.7 V8.
I probably wouldn't have another 'replica' car though, whether it be an Audi/S, Mercedes/AMG or something else. It would have to be the full fat version and nothing less. I admire all the hard work and £thousands that went into accurately upgrading mine to look like an S8 but at the end of the day I never liked coming clean to admirers and showing them under the bonnet and explaining why it 'only' had a 3.7 V8 rather than a 5.2 V10.
As for declaring insurance modifications, I've worked in car insurance and marine insurance before and trust me, an insurer will leave no stone unturned to try and get out of paying a claim, they're not stupid. Luckily for me, a benefit of my job is that my personal car can be insured through the company and they will pay the premium. So I took them up on that offer and truthfully declared every mod the car had. Different rims, brakes, bumpers and lights, grille, mirrors, bootlid, exhaust, tints, even the fact it was lowered ever so slightly too
