Hi All,
It has been a while since I posted as I usually just lurk, but now I have a question.
I already looked up the topic in the library, but couldn't find an exact answer.
I know that the older cars use blue g-11, and the newer use "red" G-12. 
Mine is a 98 GTI and my reservoir says G12, so that's what I need.
I got(well My wife actually did as she works right there) from the dealer what I was told is red g12, but to
me it looks purple. I took a paper towel, rolled it up, dipped one end into the car and one into the new
bottle, and sure enough the old is bright pink and the new one looks purple to me. 
The bottle is part#g012a8Fa4 I looked it up online and it is listed on
www.vwparts.com as "Antifreeze ( Purple )"
What is the difference between this and g012a8Da1 that is talked about in the library?
I'm guessing that the F instead of D means it is a newer version. I think that the 1vs 4 at the end is just
the size of the container.
Is it ok to mix the Purple and Red?
Thanks,
-Anthony

i've had a slow leak in my coolant system, requiring about 1 bottle (litre?)
every year, year and a half..i've purchased 3 total bottles, and all looked
the same (not quite red, but more pink).  i've never seen the purple, and
i've seen a few mk4 VR6s (not the new 24v) and they also use the same
pinkish red g12..

i went down to the garage and looked at the container i have now:

pentosin G001200
p/n:  zvw 237 g21

to be safe, i would say take it back and get the pink/red g12..
good luck !

Konuas
98 GTI-VR6, leaky thermostat edition

I spent 30 minutes on the phone with the VW tech support number and they
claim that the g012a8Fa4 is the correct  coolant to use and that it is
purple and replaces/is compatable with  the pink g012a8da1
Thanks,
-Anthony