Right.. Nitrous insurance.
Rung Adrian Flux 'Modified Cars' division to get a quote for my car: 1996
2.0 Mondeo, currently with Alloys, air filter, exhaust mods.
To insure as is: £266 (fully comp, protected NCB, £150xs)
To insure with +50bhp Nitrous: £329 (same conditions)
Hmm. Nothing there to scare me off....
Of course I am very old, (41) which helps ;-)