I just noticed on a quick run to the local shop for Cider where i HAD to take the Spyder (well... it wasn't raining so it just _had_ to be done
), that when i get above 55mph the slack is taken up in the current bonnet straps as bonnet lifts slightly due to the air flowing over it causing low pressure (There's a diagram in an Air Cadet ACP somewhere for anyone who cares) therefore creating a more aggressive angle on the bonnet and therefore causing the front end of the car (that isn't be sucked upwards) to be pushed down more and creating better front end grip!
At least that's what i beleive it's doing based on what "some bloke" said on the interweb!
Who needs multi million pound R&D studios, you just need a couple of talented blokes from Poole and a shed load of filler!