No, the V5 will be tricycle but it will be treated as a motorcycle to drive and a car to use. So you should not park in Motorcycle bays and all the other naughty things I suggested and likewise in theory you should pay tolls bikes do not, unless Trikes are officially listed as free (which they never are as no one thinks about them when setting down the tolls even if they should be on the list of exemptions). Note a motorcycle and sidecar are not a tricycle for MOT, one is class 2, I think, the other class 3. Registration is also differentiated. It is DVLA who have ignored this prior demarcation by now suddenly reverting to trikes being bikes as they were back in the 50's along with no reverse etc etc.
For number plates Trikes had the option of Bikes or Car size plates. What I am saying is with this decision trikes should uniformly have Bike size plates as DVLA say they are bikes. In effect they will be breaking their own rules by not insisting on it, in the same way as you cannot move letters and numbers on a plate to make words. The numberplate form is not part of the MOT test. Funnily enough colour is. So wrong plates, no one is interested. Wrong colour, fine for not notifying DVLA and money please.
Perhaps UKIP might want to add sorting out DVLA into a system that makes some kind of sense into its manifesto.