Thinking of buying a 325ci coupe with 100K miles.

somehow grab hold of the broken bit with long nosed pliers or something and open it from the inside ,invent something to do the job as no key slot on the outside of the door

BMW says that the transmission fluid is permanent. However, you have to keep in mind that they do not greatly care whether a car lasts 200k miles or 300k miles, so long as it makes it though the warranty period.
BMW also said that the previous generation (e36) fluid was permanent, and that has proven to be untrue.
I believe that the 1999 323 uses the later, really expensive, synthetic transmission fluid, so brace yourself for a hefty bill.
I recommend replacing the older generation fluid every 50k miles and the newer generation (yours) fluid every 100k miles. My wife's 330 is approaching 100k miles and I intend to replace her fluid soon.

I would recommend spark plugs every 30K, Trans. fluid and filter change every 60K, Brake fluid flush every 100K. I usually only flush the power steering fluid if yhere has been a component failure causing fluid contamination. Coolant should be flushed every 5 years or 100K, and rear differential fluid changed every 30K. I have several of these cars come in my shop with 200-300K miles. They can be very reliable if maintained properly.

you can get 250-300k easily out of a 5.0 of the engine is properly maintained.
Thank you,
Lee

I don't think they have a service interval. They usually last a long time. I would guess 150,000 to 175,000 miles. Or about 250,000 km

V8 engine,on the norm,will last a good long time,if they have been taken care of,and continue being maintained.Highway miles of course are always a plus,when asking about the vehicle,if the truth be told,but look,listen,and drive is the best way to be sure of what you are buying,the ignition switch is a good place to observe,the lock,and key cylinder,is it worn>is the key worn?the wrighting on the key,and it`s trademarks,are they still there,or worn off,and how bad?This will tell you if it was a start and go vehicle,or not,could be a vehicle that was drove long distances instead of short stop and go .

Check the following :

BMW Code PO128
This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Similar codes: P0125
In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant

temperature (ECT) sensor reading, and the speed of the vehicle.

You will likely not notice any drivability problems other than the MIL illumination.
A code P0128 may mean that one or more of the following has happened:

• Low engine coolant level
• Leaking or stuck open thermostat
• Faulty cooling fan (running too much)
• Faulty coolant temperature (ECT) sensor
• Faulty intake air temperature (IAT) sensor

solutions
Past experience indicates that the most likely solution is to replace the thermostat. Verify coolant strength & level

• Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
• Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
• Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
• If the above items check out good, replace the thermostat

this sounds like a water blockage, take off the water hose that goes to the engine block, start the engine, and see if there is water flow going to engine...if this is the problem, then you need to buy an engine flush fluid, and flush out your engine....please be carefull, as the E36 320i, has an aluminium head, and is easily warped by heat

That question is like asking how long I will live. How well it was put together when it was built, how it was maintained and how hard it was driven are important factors. If it's a 4.0, those engines last well over 200K if maintained...transmissions are unpredictable.
I do suggest that you change ALL fluids in whatever you buy, to establish a "baseline" for future service.
Every time I get a different vehicle I dedicate around $300 just for that purpose.(and routinely go well over 300K with every one.

If the car is having trouble maintaining idle (the tach dips and car dies) the common causes are the idle control valve and camshaft position sensors. The cam sensors failing will be indicated by a check engine light.

The ICV can removed and cleaned with good results (I think there is a write up on bimmerfest) or purchased new for about $100.

While you are in there check the intake boot that is Y shaped for cracks, it's prone to fail and will mess up your idle too.

read up on the major forums and you'll get more info