If Motor Trend is any indication, you lost the bet. 13.3 for the STi, 13.1 for the Cobra.

http://motortrend.com/roadtests/sedan/112_0410_evowrx/index9.html
http://motortrend.com/roadtests/coupe/112_0305_cobvet/index3.html

I also happened across this article, which may well be what you were thinking of: http://www.caranddriver.com/article.asp?section_id=4&article_id=1801 - but it's a first-gen WRX with $13k in upgrades.

A friend of mine who has a '98 Vette (~13.5 sec 1/4 mile) called me up one night asking if I knew of any "import grocery getters" off hand that are really fast. I said "Yeah, the WRX STi or Mitsibushi Evo".. He said "I think it was an STi.. F'ing thing blew my doors off! Twice!" He really didn't enjoy hearing that it has a 2.5l 4-banger. He later ended up talking to the owner and found that it has quite a few upgrades.. They're cool cars.

'99 Contour Sport V6 MTX