On the original subject, there is such a thing as a 'voluntary' SVA test, perhaps given the recent events it might be a good idea to voluntarily put your car through an SVA test if you have done substantial mods, then if the worst does happen you have a more of a leg to stand on, if it fails SVA then you shouldn't really be driving it anyway...
NB this applies to the 'commercial' test only, I wouldn't like to put a landy through the car test, the SVA man can keep his balls to himself
Just my 2p
Mike