OK, it doesn't matter whether there is oem or aftermarket coolant in there. It doesn't matter whether there's a mix of proper or improper coolant in there either.
There are two things which dictate the system s/b flushed and the fluid should be changed.
First, you have no idea what's in there, that alone dictates a need to service the system.
Second, save one (Evans NPG - waterless coolant rated to 500k mi.), no other coolant currently in use is rated at more than 5 yrs./150k mi. (incl. Porsche brand) whichever comes first.
Many Boxsters are now coming to the end of this useful life and the coolant in these cars is not running up to spec in either lubrication or corrosion protection. It appears that this is one maintenance item overlooked by many owners and we have seen several reported cooling system failures recently. Is this just coincidence, or is this the result of running 'used up' coolant?
The alloy components used in the Boxster (to save weight and improve heat transfer) are in some cases almost paper-thin and require proper lube and corrosion protection much more than the copper/brass components used in the past.
It's not a big deal for a DIY, or expensive as Porsche repair goes, so just do it and take your mind off of it.
