Main things are indicators must be amber, running lights on the indicators need to be disabled, if there are no side repeaters then they'll need adding, you might have issues finding a licence plate that fits the bumper's licence space, you need to add a read fog lamp and there's probably a few others too. Fortunately the 350Z is available in the UK so you'll be able to source new light clusters etc (to effect the amber indicators).
The other issue is that to avoid paying both import tax and duty (in the UK I think the combined import and duty is 35% - I could be wrong) you need to have owned the car for 6 months I think. I'd bought my car from a friend then visited the UK for holiday and decided to move back home, so I'd only just owned the car for 6 months when I finally moved back.