The is an extract from the VOSA SVA documentation;
“After arrival the only circumstances in which you can drive the vehicle before completing the registration and licensing formalities are to and from a pre-arranged SVA and/ or MoT test and to and from a garage for remedial work following failure to pass the tests. Other than in these situations the vehicle must be kept off the road until the licensing and registration formalities have been completed. N.B. UK law requires a vehicle to be licensed and registered for use on the road. To avoid difficulties, importers are advised by DVLA to transport rather than drive their vehicles from the port of entry to home or first destination and to keep them off the road until they have been properly licenced and registered.”
It stands to reason that you should have insurance in place to cover you if you do decide to drive your kit car (make sure it covers you for this particular scenario, ie car is unregistered and driving to SVA test centre).
Have all documentation with you to prove that you are driving to/from a pre-arranged SVA or MoT test and don’t take the ‘country route’ to get there.
Best advice is probably to trailor you kit car to and from the SVA test or get a recovery firm to do this for you.