Airbag light is no biggie...
Brakes are wear and tear on ANY car and I would'nt worry about.
For a 318i of that year and milage (I just bought my 318i with the same milage and year last june 2004)
you want to look at:
1. IN ENGINE BAY:
Dirty engine bay is a turn off, look at BELTS/FANS/COWL TRIMs for normal wear and tear. These are important items for this car. I'll put other important items in caps below.
-Locate and check IDLE PULLEY TENSIONER and ICV (IDLE) and asked if it was serviced...the issue here is idle problems that are common with 318i. Also ask about Air Mass and Oxygen sensors. Any problems or issues in the past. That is something that usually fails on 318i after 7 or so years. If it hasn't expect to be fixing that issue soon. I wouldn't worry about OIL and OIL changes. It is important, but it's a matter of how you trust the seller...who could be telling you anything. If you have any doubts just do a full oil flush and service with other fluids such as power steering, brakes and tranny fluids. it's about $100 at any good place and will give you peace of mind knowing the car has good stuff in it.
-POWER STEERING FLUID, check the reservuoir and hoses underneath it for any leaks or boiling/dribbling over (this would be a sure sign that the previous owner didn't use the right ATF fluid.
-RADIATOR: Only thing you MUST DO is make sure the fluid is not bright green. BMW reccomends that 3 series prior to 1999 use BMW- ONLY coolant which is blue (or blue green if old). The bright green coolant WILL mess up your hoses and radiator after several years of putting it through your car's system (especially if you live in region where the temperature get hot in the summer and very cold in the winter). If you see green ask the seller about it about it and if you buy the car do a coolant flush immediately and replace with BMW dealership fluid. Remove spark Plug cover and check inside for dirt, leaks or wear. Also check the
-DME foam cover and region (above and behind the battery terminal) for wear and tear or if it was opened before. If you see signs that someone opened or damaged the foam ask why.
-FUSE BOX Check Fuse Box and relays for dirt, burns, and tampering or unusual modifications.
VIN NUMBERS-Check the side of the bay where the fenders are bolted onto the frame. It will be a narrow channel there where the hood comes down and seals, look for VIN number stickers or stamp on the metal part. check both sides. They should be there on both sides. if missing it's a sign that the original fenders were replaced...ask why and what happened.
2. CABIN AREA:
Check seatbelts buckle release device. There is a date enscribed on there on the inside. If the date is later than the model year of the car( say a 1995 318i with a date on the buckle realse that says 7.15.1998) ..that is a sign that the SRS system was replaced/modified/failed or something happened that was serious enough to have that replaced (this could also be but not certainly a sign that an airbag was deployed).
Check FRONT SEATS for FULL range of motion if manual, power, heat, sqeaks, looseness and wear and tear. Check steering wheel and the obvious stuff on the rest of the dash. Check GLOVE BOX for parts (flashlight) and dirt and check if lid is loose when box is shut.
Check and Lift ARMREST and remove cupholder/coinholder/ashtray CONSOLE (just lift it up it comes out) look at the space under for unsual modification, money, drugs, burns, spills, holes, spiderwebs, etc...(no kidding I found a phone wire and jack modification, a wired and working light bulb socket built in to the console, a small box of business cards of the previous owner, lipstick, lots of hair and coffee dribble under my car's armrest console)
Check WIRING underseats to see that the AIRBAG SENSOR (under the passenger seat) is connected and wired. Even if the AIRBAG light comes on (if so it usually stays on for 3 minutes after starting and driving the car)...it doesn't always mean something malfunctioned but only that a wire was loose at some point but reconnected. Just check to see that the wire is still connected and try to reset the light if you buy the car.
Check ALL DOOR PANELS for rattles or loose clips, Lift up REAR BENCH SEATS-ON SEDAN MODELS ONLY (pull it up, with both hands gripping under the middle area of both sides...it pops right up)...underneath on the passengerside you'll see a cut out for the FUEL PUMP DOOR, in the middle is another MAIN AIRBAG SENSOR device (not sure myself what it is exactly :confused ..but it is well labeled and it looks important :blink: ) they'll be a bunch of important wires around as well, check everything for tampering, wear and any unsual modifications. Especially, check the fuel pump door. If that pump was replaced before they'll be clues there.
Check the obvious sunroof, cabin lights, ventillation, AC, dials knobs...don't sweat missing dials and knobs on the E36 dash the are easier to replace than any blown bulbs behind the dials and guages and definately cheaper than replacing a tampered fuel pump or SRS device.
I don't like a dirty cabin... :sick like oil or kool aid stains on rugs and panels or extreme weathering on the leather seats and door panels (as if the windows/sunroof were left open alot and rain water got in on the seats). It tells me that the previous owner didn't care about simple sanitation and cleanliness of their BMW and probably was ignorant of other more functionally important things that you can't visually inspect.
3.TRUNK: Check REAR SHOCK MOUNTS. If the seller doesn't let you peel back the trunk lining to look at them. You can still push down on the corner and check how the car bounces but MORE IMPORTANTLY listen for ANY metallic clanging from the areas where the mounts are. If you hear anything you are looking to replace shocks and possibly re-weld the mounts (more expensive than brakes).
Check Battery for leaks (obviously) and wiring for wear. ALSO remove rear light covers and Check BRAKE LIGHT BULBS and BRAKE LIGHT SOCKETS for burns, wear, fluid leaks (signs or rain water getting in). When done check seals and Trunk lid shocks. The trunks on BMW E36s lock kind of funny so don't be alarmed if the trunk don't lock or open how you would expect.
ALSO you should also check FUEL DOOR LOCKING MECHANISM. The fuel door should lock with the the car being double locked.
4. EXTERIOR: check the obvious scratches and dings etc... rule of thumb the bumper areas are plastic and not metal and in theory should be cheap to detail but I've always gotten prices like $100 to $300 to detail the E36 bumper.
5. UNDERNEATH: check BALL JOINTS..if they are loose or shakey...not good...but not bad..you'll just i'll have to replace them. check for heavy rusting or loose parts. There's is other stuff but someone will add to this.
You guys are welcomed to add to this list...I will Pin it later on.