I bought an RAC warranty when I bought my car and the more I think about it, the more i wonder if there's really any point in having a warranty - taking in consideration as to what it covers? Nearly everything that will go wrong with a modern car comes under 'wear and tear'. However, my warranty was the standard £300 job - looking at the RAC website - they have a 'Gold' option, which covers a massive range of problems - even things which most dealers would call 'wear and tear' under their manufacturers warranty.
http://media.rac.co.uk/pdf/6071-rac-warranty.pdf