It will depend on the depth of the recess between each of the stud holes in the wheel. So check that first - others on here can tell you if you say what wheels you have.
I recently had that issue with the 370 wheels. Whereas the recess in the GT rear wheels was probably in excess of 20mm deep and therefore readily accept the standard studs poking the 5mm through the 20mm spacer, the front wheels had less than a 5mm recess so the answer was to add a 3m slip spacer to ensure the wheel fitted tight on the spacer. Ended up with 23mm 'spacers' but 3mm is neither here nor there in terms of the overall effect.
3mm slip spacer used
The 20mm black spacers were supplied (and helpfully fitted) by Andy of Kudos Automotive