hi guys my new 2004 tdi a3 has got a hell of a noise im fairly sure its the n/s/f bearing but not had time check it yet. rang around and can get a genuine for £100 from tps. or theres cheaper ebay ones. i think the part number is 1T0498621 but ive seen some for cheaper with number 1KO 407 621 C will this fitt? also are they hard to do yourself?