Mercedes Benz repair: Smell of oil/petrol, transmission oil cooler, engine oil cooler

Question
I owned a Mercedes 200E model. The inside of my car will smell
of oil/petrol everytime I turn my car on and drive around. The
smell will get stronger when the car is in idle position (traffic
lights etc). Please advice.

Answer
What year model, and what country?

This could be:
A dangerous or serious petrol/oil leak.
A cabin/engine compartment seal.

The following is a generic advice.

Inspect your:
* Fuel hoses and lines from fuel tank to engine.
* Valve cover gaskets.
* Timing cover gasket.
* Oil pan gaskets.
* Oil stick seal.
* Front and rear crank shaft seals for leaking oil.
* Engine oil cooler lines.
* Transmission oil cooler lines.