The other day a garage replaced a cracked cam cover and after getting the car back, I started smelling what I thought was oil through the vents. Took it back to the garage and they said they couldn't smell it nor find an oil leak. So I took it home and thought I'd just have a peek underneath..

Is that oil or fuel? Is it dangerous to drive?

My guess is it's gearbox oil.... and that's because the gearbox seal may be damaged.

Happened to me as well! If you search the forums for "Gearbox leak" you will find my post. I used an YouTube video to see how to change it. Good luck

That looks like oil to me. Wouldn't say it was gearbox oil as the gearbox is at the other side.

Is it coming from higher up or is it just that area? If not then I'd guess at sump?  Either way the garage did well to miss that...

looks higher than sump and def engine oil. what engine is it ? looks like a 1.0 ecoboost? 

I will have to agree with the guys! Did not see the proper full size picture on the phone. I would go with engine oil as well. It's leaking on the drive shaft intermediate bearing which is halfway between the gearbox and the wheel. Clean it up properly, and do a few miles with it, then see where is it coming from.

It's an ecoboost, yeah. I'm not educated about engines, so couldn't tell you where it's coming from. Not that I can see it myself. I can't see any pools of oil or splatter from the top. If I get right under the car I can only see drying oil in places. Maybe I can get my phone under there tomorrow for some better shots.

A friend of a friend said it might be where they've fitted the new cam cover and cleaned off the top but not the bottom. Might get some brake cleaner and test that theory.

your friend could be right. probably some oil residue from the the original oil leak on the exhaust was what you could have smelt  burning off.