5 stud alloys on a 4 stud?

hi guys, posted this in mk3 specific forum but had no answers in days and was hoping to buy soon if theyre suitable
i've seen some fk hubcentric spacers on ebay which will allowme to put 5x100 alloys on my 4x100 golf gl so i want to use these put mk3 gti alloys on, however they're 15 or 20mm wide.
will this space out the wheels too much for my arches? im finding it diffult to find info on offset, and even then dont know if a little bit will improve looks anyway!
its so i can put mk3 gti rims on my GL

thanks :beerchug:

hi, sounds difficult, not the sort of thing you would want if you were stuck on the hard shoulder at 1025 on a rainy monday evening with a puncture, ware on e bay are these for to five stud things