They are 5 1/2J wide so same as Sei Abarth wheels, and check the off-set the Punto GT wheels i had were offset 45mm so you need 15mm spacers all round and still retaining the 3mm standard spacers up front to acheive the correct 30mm offset, or if running 185/50 14 rubber then aim for same offset as Sei Abarth wheels which are offset 36mm no spacers on rear, but have 10mm spacers on the front, so front off-set 26mm, so 10mm spacers on rear as you will not get 9mm ones and then on front 20mm spacers losing the 3mm ones this would give rear offset 35mm and front offset 25mm, only 1mm out from Sei Abarth set up.
HTH, Aaron.