Hey Doc -
Yes, they will fit - I just put Pirelli P-Zero's on, size 285/55/18, and they fit like a charm, no trimming. I love the head on and view from the rear, but I'm still not used to the side view, though. From the side you see a lot more sidewall because of the way the tires bulge out from the rims instead of going straight up like the 245's did. I always hated the view from directly behind with the stock tires - they looked puny and made the VX look cheap/sickly. I think the guy who put the tires on summed up the new look the best - "man, that thing's a little beast!"
The 285's come out close to the edge of the cladding and look like they belong! With the 285/55 (as oppossed to 60's) you get very little height difference, so little speedo inaccuracy, and NO TRIMMING of the cladding needed! you'll love the look when you get them on!