It might be as simple as reseating the coolant cap and tightening it down a bit. Some dealerships will top off fluids before letting a car off the lot, and they may not have seated the cap properly or tightened it down all the way. That's actually what happened with mine when I bought it.
The seal on the coolant caps is also known to fail over time. (Provided that you don't see an issue with the coolant reservoir) I'd order a new coolant cap to be safe (blue Porsche OEM - do a search to find the correct model). I'd also order a new case cap, because the seals on those fail over time too
