Slight coolant loss / intake manifold

Just had MOT done on my octy vrs mk2 , non facelift. When up in the air,  annoyingly they spotted drops of coolant that formed near or on the oil filter housing wasnt even dripping.. no engine splash guard. So they failed the cAr just for that, though my rear right caliper is binding and squeeling but that wasn't noticed. ( A job I'll do myself soon)

So far I haven't noticed a dip in coolant levels, so it's really a misting of coolant underneath and minor that I can tell. I can't get under the car for a few days to look properly, though I don't know where to check in all fairness.

In the summer driving to Poland, I got an engine warning light pop up on the dash, I had my scanner and it told me intake manifold control runners something or other, I cleared it and hasn't come back. There is since then a howling noise under acceleration especially when cold, so I suspect the gaskets on intake manifold are starting to go, do these also have coolant running through them? Turbo seems ok I don't think it's this. 

I could do two things, one is nothing, and buy / screw on a engine splash guard and keep close eye on coolant levels and wait for possible issue to worsen then take action..  or it might be fine like it is, but taking a chance.

2.go to the stealers and get system pressure tested, see where slight coolant leak is from and get them to fit a splash guard whilst it's there but £££ I'm sure. 

Any thoughts? What would you guys do?

I plan on some summer trips and may be piece of mind is best but I don't want to fritter hundreds away at the stealers, I can fit a engine splash guard, radiator if needed, and small things ,  but replacing intake manifold is out of my league.