Hi mate welcome to S.O.C Not sure what the smell might have been I've not had the please to test drive one but if I was going to get one either white or the darker grey colour would be my two choices. We have a fair few people with the newer STi so hopefully one will belong to give any advice. @Sparky has a nice build thread going. Well it's had a bit of a hiccup but certainly worth a look and ask away I'm sure he won't mind ;)
http://uk.subaruownersclub.com/forums/topic/15637-sparkys-2015-sti-build/