[Perfectlap]

wait a minute, I couldn't make out the part number before. But I see you have the 04 cap. That is the most recent. They may not have vacuum filled the coolant tank, did it the old school way and it wasn't burped properly. You have to run the car up to temp, let air out. Do it again. And again.
If its done in a hurried way you'll end up with a bubble in there. And a bubble in there could split the coolant tank just a little bit (for now) so that you get a drip leak. It could eventually split open the old, brittle, original coolant tank and spill all the coolant while you're driving -- $600 and a tow (ask me how I know this). So they need to check for leaks and get out the air. If they did fill with an Airlift like most Porsche shops that know what they're doing, so that all air is out, and you have the most recent coolant cap to ensure an air-tight seal then you have a leak somewhere else.
Check the dip stick like I said.

p.s.
If you're near North Jersey (Newark Airport) try R.O.C.S. in Belleville. They do vintage Porsche and new Porsche.
In-house lazer alignment, no touch wheel mounting, they work on Rolls Royce, Bentley and BMW as well.