I'm with Chris Knott as well, 25 with a 2005 Vectra C 1.9 CDTI SRI, Tuning Box, Simota Induction Kit, few bits of Irmscher Kit fitted, and it's costing me £570 with 4 years no claims.
As Neil said, take a look at the link to our Insurance section, we have a scheme set up with Chris Knott and Adrian Flux