I'm not familiar with your car, but what I notice is the 3rd picture of the power steering reservoir. Are the leaks around or below that area? Maybe it's a power steering fluid leak? That happened to me and bought new O-rings for the cap and that fixed it. Check the power steering fluid level.

 

Definitely check the power steering hoses too- They look like probable sources. Check the fluid level to confirm then wash the area clean and run it to confirm location. It might be a connecting joint leak or hose that was rubbed through.

 

On the last picture you have oil around two VVT Solenoids. Clean it with brake clean and see if its leaking from VVTs. They do have o-rings.

 

Vacuum pump and/or oil pressure sensor?
Check the bottom of the vacuum pump with your hands.

PS reservoir: the "residue" can be because of the bad gasket on the cap... but it's a lot of oil for just a cap seal.

 

Mine was like that. And I caught it early. Here's the thread on mine:
https://5series.net/forums/topic/120...1#entry1412360

 

I am getting my car's engine compartment cleaned up by bmw so that I can spot the leaks more clearly and do the required.
any suggestions what I should get done before I get engine cleaned up.
obviously, I want to go for not very pricey changes.
BTW I just had engine oil/filter changed about a week ago.

ThaNKS!