I have imported 3 cars from Japan, 2 x Mitsubishi GTO's and the best and quickest car I have every owned a 1997 Mitsubishi VR4 what a piece of kit that was, owned it for 4 years.
I have never used tradecarview, I have an account with idirect,
http://www.idirect.co.jp never had a problem at all. Couple of things to remember, in Japan they change their cambelts on mileage, not age. My VR 4 had 45k kms on the clock when I got it and was on its original belt so budget for that. There are two main islands in Japan, the southern are temperate, they very rarely get ice and snow so these cars don't get the salt, however Japan is an island so cars that are owned on the coast suffer like they do here.
There are grades which are supplied with used cars:
Grade 1-5 is condition of body work 1 = Junk 5=like new I always buy a Grade 4
Condition interior A-C A = New C=Dirty and damaged
Underbody A-D = A = New D=Heavy corrosion
Companies like idirect look after all the paper work and import to Southampton or Bristol, I always go into Southampton, budget for a £50 paperwork fee at this end, Vat at 20% and import duty at 10% of total cost including shipping.
Conversion is straight forward, over 10 years old from first registration no SVA needed, at the docks is a company called SVA UK they will collect it if you want and do the speedo conversion and the fog light, they built my fog light into the rear light cluster very neat job.
Then you need to get the registration document from DVLA to register, not sure the number but you can get it from a post office no problem.
Fuel remember Japan cars are mostly tuned for Super Unleaded that means Tesco 99 or Shell V-Power.
Rust proofing is recommended but easy enough to do on a dry day and a ramp.
Some people say that cars from Japan are clocked, though this is true of some, Idirect warrant all their cars mileage, any issues you get a refund even if its been landed in the UK. Also I work for a Japanese Bank in the UK and the reason for the low mileages is that people commute by public transport more than we do also their road charges are horrendous, want to cross a bridge or use a tunnel that will be £25 please each way! Also their cities have congestion charges and car parking makes central London look bargain basement. They also never or hardly ever tow things, they don't do caravans and the like so very rare to find a tow bar fitted even to a 4x4.
I am also importing a Subaru next year, going for a 2004 GT-B estate never came to the UK so nice to have something a bit different. Good luck happy to answer any other questions you may have.