I fitted
Continental Premium Contact 7 V rated in that size late last year Les and very impressed with them. The reviews give them top marks wet and dry. The OE ZV7's started out ok but hardened up after five years such that I was getting wheel spin in third at the slightest sign of road dampness. You could feel the softer rubber of the Conti's even before fitting.
I believe there are several other Roadster 3.7 owners that have fitted them. There are more exotic tyres, maybe grippier still but not in 16 inch size.
