Right this isnt realy audi specific but Im getting a maf error on my A4 and decided to try and clean it myself anyways Ive stumbled at the first block. The sensor seems to be fitted in with a Torx style bolt but it only has 5 points, not the usual 6, it also has a security hole in the middle of the pattern. Does anyone know what this type of screwdriver is called or where I can get one in the UK? Thanks for the help. Pete.