Yeah you can, i'm down as a second driver on the missuses puma and ive got four years ncb for my name..she's got 9yrs ncb (dont know what the min is for full no claims...is it 6yr?), thats on a Direct line policy. tbh it was news to me when I was told by direct line that i could carry on my ncb from my old daily driver when i went onto her policy, but its in black white on our policy docs to confirm.