I don't think many people use protected cells in vape devices anymore. Samsung, LG, and Sony all have high quality IMR cells. Why people choose to cheap out on batteries in a device they put in there mouth is beyond me.
MK4 since that's the MK that got me interested in these cars. 3 of my friends had MK4's right out of highschool and I always liked them. I got my MK6 years later, And now like my MK7 even more than the 6.