My 2007 335i is the best driving car I've ever owned.  After the HPFP issue was resolved early on I have had no mechanical issues with it at all.  Battery has been replaced once, and that's probably because I've left the fob in the ignition a couple of times in the garage.  Set of Michelin Pilot Super Sports were only $1k installed by my local chevy dealer.

When I sold insurance one of our friends/clients bought a new 3 series.  The thing absolutely ate tires.  It needed new tires after about 5k.  They took it to the dealership who said something had to be wrong.  BMW put new tires on it, and after a couple months they were wearing as bad as the first set.  They went back to the dealer who couldn't figure out the issue.

The dealer ordered some parts and said let us keep it for a couple weeks and see if we can find the problem.  Our friend got a nice 535 as a loaner.  Two weeks pass with no word from the dealer.  After week three our buddy got concerned and called the dealership.  

"Hey this is Mr. K, just calling to check on my 3 series and see if you got the issue with tire wear worked out."  

After a few seconds of quiet talking and confusion on the other end, the rep came back on the phone and said, "Mr. K are you sure you've got the right dealership?  We don't have your car."  

Mr. K said, "Sure you do, I've got a 535 loaner that you gave me."

"Sir, I don't see any record of your car in the last month, and I'm sure you don't have one of our courtesy cars."

After a heated exchange the rep agreed to do some checking and call back the next day.  The next day they called back and informed our client that they did not have his car and he surely didn't have theirs.  As his insurance office this is where we came in to the picture.  Our advice was that his car was insured, give them a chance to find it... but don't take the loaner back until they have his car(this wasn't a big deal since they wouldn't acknowledge that he even had the loaner)

The shit show continued for about another week as Mr. K worked his way up the chain of command.  Finally, he had given up and was looking for an attorney.  Then one morning he received a call from a very apologetic service manager.  The owners have several different dealerships on the same road.  They have acres upon acres of different types of cars.  Apparently his car was tucked away in some far corner of a service lot and forgotten.  Out of the hundreds of luxury cars they have, one white 3 series blended in pretty well.

They apologize and assure him they'll fix his car in a week.  They asked if he needed a courtesy car until his repairs were complete... he said, "don't worry about it, I've already got one."

When he finally picked up his car, he took back the loaner.  The service dept argued with him and he had to physically walk them out to the car and show them their sticker on the back window.

Did they fix the tire wear?

The IS F, RC F and soon to exist GS F exist for a reason.  And the latest is350 beat the 3 series (also the ats) in a recent car and driver comparison.

It's not a propeller.

But I'm sure you knew that already...

I thought they were the "prop and sky" to give a nod to their airplane heritage?

BMW-the manufacturer who brought dipstickless engines and a hood that requires two people to open. Yes they're nice looking cars, but for the price you pay, that car better be trouble free and give me daily blowjobs.

 

Fixaflat. Only good for pissing off tire technicians.

BMW's are NOT Camry's so they're more expensive to keep rolling but one should be smart. General maintenance can easily be done by yourself and perhaps a certain tool or two, there's no special sauce on the battery but sounds like you needed a "clearing of codes." The BMW specific tool can't be that much or find a BMW owner that has one in your area.

Run-flat tires are a crock, get a tire patch kit and roll with normal times; might be wise to carry a AAA membership or find a donut spare that works on your car. They'll ride/handle better and last longer.

What the hell, this place must be a HUGE car dealer or filled with complete morons. Was there a license plate with current tags on the loaner car or did it have dealer plates?

THIS. That 97 E320 is a TANK.  I picked up one that was in a collision and fixed it up for my stepdaughter.  Gonna need to replace the radiator soon I think.  It looked like it might have been leaking when I put the new front clip on, but it passed a leakdown test.  A year later it's starting to drip.  

I also own a 2000 W220 S500.  305HP, 380 lb/ft of torque and the car is big and heavy, with big vented brakes.  I asked for advice from some of the auto techs here before I bought it and they were 100% correct about the cost and importance of maintenance on German cars.  I drove the crap out of it all around the mid and southwest.  Got it cheap, maintain and fix it myself for the most part.  Change the oil twice a year with MB approved Mobile 1 and Mann filters.  I had the dealership replace lower control arm bushings two years ago when they failed.  This past fall I did the rest of the front end myself - upper control arms and lower ball joints.  Just did a rear wheel bearing on it and replaced the factory original battery which was 14 years old!  Have also replaced little things like a crank position sensor and side mirror weather gaskets.  Going to need to reseal the rear diff soon.  This car eats tires.  I get maybe 30k out of the rears, and it's pretty much due to the fact that I can't drive the car without doing the rocketship imitation from a stoplight every once in awhile, and doing the 60-100 roll on on the freeway now and then.......while ensconced in great leather seats, the best ride I've ever felt, next to zero road noise, some nice music on the radio, and with a great big grin on my face.  My wife drives it now, she absolutely loves it and drives it like I did.  

OP just get smarter with your maintenance.  Get yourself a battery and spend the $10 for the app to program the battery.  Forget the run flats.  The Falken tires I run have been very good to me and are only $110 each at Discount Tire: http://www.discounttire.com/dtcs/findTireDetail.do?ra=searchTiresBySize.do&fl=&tc=FALHZ3&c=2&rcz=85392&pc=15035&ar=45&rf=true&rd=18&rc=AZWINT&cs=245


ETA:  Our car has over 150k on it and drives like new (knock on wood).

It's filled with complete morons.  My wife's Rx350 was in there for about 4k in front end damage.  They had it for 2 days shy of 6 weeks.  We had to wait an hour when we went to pick it up and when they finally brought it around it had a flat tire... not low, completely flat.  I pointed it out and the tech jumped in to drive it back around the building.  I had a meltdown right there in the parking lot and sent him inside for his boss and an air tank.

I'm pretty sure the loaner had d-tags.

I wrench on my own stuff. Not much difference in my Ford, Subaru or BMW. Dealership labor is the most expensive labor there is. Your labor is free.