After getting sick of having numerous motor legal protections on household policies - me car, me bikes, wife car etc - I cancelled them all at renewal time and bought one policy which covers everyone in the household. It's this, as recommended by HonestJohn in the Telegraph:
http://www.autolaw.co.uk/ I haven't used it so can't comment on their efficiency, but the cover is actually mroe extensive than any of the individual policies I used to have.