Good point. Man I hate seeing that film, makes me shudder.
Also, you might try driving the car, getting it warm, park it and open the hood for a short while and then use your nose to see if you can detect the source.
I have almost always found these leaks by just using my hand and reaching under each hose, connection and component I can touch.
Keep us posted,
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)