Will 5x100 rims fit the 3 ??
No...The way bolt patterns work is like this. A 5x114.3 pattern means 5 lugs, with opposite lugs being 114.3mm apart. (If you numbered the lugs 1,2,3,4,5.....The spacing between 1,3 or 2,4, or 3,5, etc would be 114.3mm apart.)
The 5x100 wheels wouldn't fit.