you could go ITR or CTR 5lug conv ,,,but prolly more than yer buddy wants to spend this will run 1000buck just for parts!!!!

or you can use billet adaptors but they make you wheel stick out apprx an extra inch ,,and i'm not real sure how safe they are,,,250-350bucks not to mention 4lug to 5lug adaptors are kinda hard to find,,,but they are out there!!

tell your buddy to fall in love with a four lug rim..4x100mm to be exact