Any good third party warranty when over 100,000 miles

I have just bought a Skoda Octavia 1.6 Diesel it is a 2010 and has covered 104,000 miles.

I purchased from a dealer and got a 3 month warranty included, I've had the car 3 weeks and after covering only 500 miles the no1 injector failed and it's currently in a garage and being repaired under warranty. If I would have had to cover the cost it would have been £500!

I am now seriously thinking about finding a good third party warranty company in case of any other problems as I had to ring round a lot of garages to see if they had the equipment to code the injector after a new one was fitted - in the end It's ended up at a VAG specialist garage.

What are you thoughts, I think the AA also do something which covers some breakdowns if you pay an excess per claim? I'm just after a bit of piece of mind as it's not a cheap car to buy and by that first bill not a cheap car to fix either.