An 03 Elantra might be too old to be close to the 05 Spectra design.
The 05 and newer would be closer.
I'm surprised that there hasn't been much activity on your post.
Just looked on ebay and found that the same CCV is used in...
KIA 00-05 RIO and the 03-09 SPECTRA.
Kia 00 05 Rio 03 09 Spectra Canister Close Valve 31430 2F500 | eBay
It looks like the square base of it may slide onto a metal prong. I have seen where the prong has barbs on similar mounts.
They are an expensive little bugger...around $100.
VALVE - CANISTER CLOSE. Kia # 314302F500
I also found this site in Korea that has it pretty cheap $26...I haven't read any reviews on them though...
Auto Part Item View : 314302F500 VALVE-CANISTER CLOSE for HYUNDAI/KIA CERATO(OLD)
on ebay as "koraps-autoparts"
Just some info...