I have to agree with the previous posts: Get a mechanical inspection. Being 9 years old, your insurance company probably won't require it or ask, but a good inspection will save you years of heartache and a empty wallet.
Some of the things on these cars you can do yourself in your garage (if you have one) and you are somewhat handy with tools. Do shop around online, because parts can vary widely from one store to another, and doing some good searching can net you a good deal on parts.
Now my 2¢:
160,000 on a 9 year old car is a bit on the high side, but it's not really bad. if the price is right, then by all means go for it, pending a inspection. If the inspection yields minor stuff, then buy it. IF there is some major issues, or simply alot of issues with the car, then pass.
1994 530i 5 speed - RIP due to a dipshit that can't do overshoulder checks and ran over the front end with his Jeep!
1989 325i - RIP due to a knucklehead that rammed the car in the butt doing 50 km/hr while I was stopped at a intersection!!
New ride: 1998 318i