BMW Repair: 1997 BMW 740i, bmw 740i, drive shaft

Question
Hi Don,

I have a big challenge. My 740 was making a clicking noise so I took it to a service center and they gave me a $1045 price to change the drive shaft with an after market unit. I then went to the BMW dealership and they told me that it would be about 1600 to have it done. I went with the dealership knowing that the drive shaft was going to be brand new. After four weeks of waiting, the parts got in and I took my car in yesterday. this morning they called me telling me that it needed another $80 worth of flanges and etc which was fine..then they called me in the afternoon telling me that they had challenges getting the bolts off and some had gotten inside the manifold and that would be another $200..Well that really got me pissed and I told them that I was coming to look at what they were talking about. Well, I went to the dealership to look at the car while it was up in the air, but the first thing I noticed was all the oil leaking from under the engine which was not there before..They kept telling me that it was because the car was OLD..what the heck? We have driven the car may be 200 miles in two years and it has 140K miles on it. I have been thinking about the oil leak, and now I remember that when I took it to the first service center, they had it up on the lift while looking under and I was with them and I did not notice any oil leak just noticed a screw under the lower engine cover missing. I even came home today and looked at my garage floor to check for any oil, and ofcourse no oil on the floor. What did they do to cause the oil leak? Please advise..I am really stressing out.. I believe that they damaged my car. Please advise.

Answer
Well first off did the "clicking" noise get fixed?As for the oil leak I really don't know what to say.This leak,is it a dripping leak,or did you notice the presents of oil.?The car does have a few years on it.And the lack of driving does affect it.When age comes on the cars the seals and gaskets do get hard and brittle which may cause a leak.The other thing is how did it run,if it was a bad leak(dripping)then it would have drivability concerns because it would be an unmeasured air leak which would cause the car to run rough.The gaskets used are fairly thin cork gaskets which do after time leak,how much well that is hard to say.A small oil leak does look bad and if there is no oil on the floor it maybe just in the beginnings and time to repair before it gets worse.Do I think they did anything to cause it,with what I have I would have to say no.I am concerned if the repair of the clicking is fixed as you put a ton of money into that repair.