Oil and transmission leaks
 

So with this whole turbo wastegate diaphragm thing, my mercedes has been sitting over fresh concrete for about a week. With the obvious result. My question is what would you think is leaking judging be the oil puddle positions?

Directions referenced from sitting in the drivers seat, as normal.
Now I'm looking at the front, left spot and thinking oil cooler line.
The middle spot I'm unsure about. Something is leaking onto the crossmember and idler arm.
The right oil spot I'm thinking the CCV drain fron the air filter housing.
The transmission I don't know about. I replaced the O ring on the modulator, hence the lack of fluid on the left side. I'm not sure what would leak on the right.

Oh, and the large rear puddle is transmission fluid. All other puddles are engine oil.

You are coming real close to disproving the theory that there is no such thing as a dumb question.

Thanks for that incredibly insightful answer!
Think about it. Non running car, so oil seeps out rather than spraying. No air flow to redirect seepage. So we're talking gravity flow only. You should be able to trace any given puddle to a source. I've already had a suggestion that I check the transmission dipstick mount, since the puddle was on the right side of the car rather than left. Makes perfect sence, if you know where the dipstick mount is, and if you know that it can leak. I didn't.

So, with regard to the oil spot near the front/left, is that an upper oil cooler line spot or a lower oil cooler line spot? Or is it oil from the injection pump gasket which runs down and eventually drips off the a/c compressor? Or the vacuum pump?

i would clean everything off real well with a degreaser, then i would put fresh cardboard under it and after a while check for the leaks...

Now this is what I had in mind. You evidently know a hell of a lot more about these engines than I do. I didn't even know the IP had a gasket to leak from.
There's a moist spot on the upper line, so it is probably leaking a little. If I've heard right finding a local hydraulic line shop and asking them to rebuild it is the best way to fix that.
Ok, if I clean everything and suddenly find oil on the A/C compressor I know to suspect the injection pump gasket now. I'll bet that's a pain to do. And probably affects the timing?
Vacuum pump? Does it leak at the gasket, shaft seal, other?

You are not going to be able to conclusively diagnose oil leaks on the basis of spots on your garage deck. While these spots may provide a good starting point for your search, your time will be better spent looking inside the engine compartment. And even then it can be a challenge to trace the actual source of a particular oil leak. One problem is that the oil tends to run down various components and does not actually drip off until it reaches a low point, which could be quite some distance from the source. Some potential sources are ijn close proximity to one another. The drainback tube from the air filter, for example, is right next to the turbo drain. A leak from either one will run down and drip off the lower oil pan, making it look like the pan gasket is leaking. Same concept with the oil filter stand/turbo oil line. And a leaking valve cover gasket can really add to the confusion.

These cars are leakers man. I think that after 25 years the various oil seals and gaskets are ready to retire. You should degrease the engine well, especially underneath above and below the oil pan. After you do this you can see which gasket or seal is the likely culprit. Look at:
1)Valve cover
2)Oil cooler fittings
3)Front crankshaft seal(behind front main pulley)
3)Turbo oil drain seals(look above the oil pan mounting flange on the passenger side) - these can make a mess and are a usual suspect
4)Oil filter housing gasket - this will be tough to look for, It can leak down the back of the engine, or it can find a path down the side, can even find a way to run down the other side
Also, the rear main seal leaks in these engines, which you can't do anything about unless you want to pull the crankshaft out of the engine in such case if you're like me you would probably go too far and go for a complete rebuild. All on account of a few oil leaks. So if you don't want to blitzkrieg it and replace all the seals(if you plan to drive the car for years to come you will eventually end up doing this) then you will have to very carefully and thoroughly clean the engine off and trace the source of the leak. My guess is it is leaking from more than one place.

True, but I'm still learning about oil leaks, which is the primary goal. You guys can't wrench or inspect the car for me, but I can learn an awful lot from you. Like the crank seals d.delano mentioned... not that I wanted to hear that. :(