Join Date: Jul 2007
Location: New Zealand
Sometimes it's as easy as pulling the pedal up hard against its metal stop. Often the switch is designed to self-adjust, being pushed out of the way so that it is only just in contact with the pedal.
Either way as you'll have figured out, at motorway speed the difference between the brake lights coming on when you first brake versus a half-second later is surprising - maybe it could make the difference between a near-miss or not. With the switch removed/activated, it's also a good time to check that all seven bulbs in the high-level brake light (Spider; GTV might be different?) are working. They are 2.3W bulbs, a little hard to get but brighter than the usual 1.2W bulbs.
'00 GTV V6, '08 FIAT 500, shell and parts for a '71 FIAT 850 Coupe