I have been a bit of a 'lurker' on this sight getting information and advice before buying my 2001 E46 330d SE Touring.
It has a full FSH and have had various parts replaced over the years.
It is about to have a check over at Steve Rowleys in Cheltenham http://www.bmw-saab.co.uk/ as I noticed a smell of diesel and a slight leak of diesel next to one of the injectors. It is also going to have a swirl flap check as I need to know it is OK. It is the 184bhp 330d Manual Touring so it should be OK.
As usual the parking sensors don't work, but everything else does for a 9 year old car with 137K on the clock.
A word of advice when buying a second hand car.. I looked at 16 other cars before I found this good one and found that many of the sellers were using the images from when they bought the cars!! One seller was using pictures 5 years old! Check the service history, check the VIN and V5 details thoroughly and don't be afraid to check that everything works, or not. If not, if the seller is asking for top money, then use it as a negotiating point. I did. I got a good amount of money off for the parking sensors and the diesel smell under the bonnet.
Otherwise, the car is superb! Done 1,000 miles in 2 weeks and it hasn't missed a beat. Looking forward to many, many more!