I notice that you mention it is a PCP agreement and would urge you to consider that half of the total amount payable includes any 'optional' Final Payment due at the end of the term. If (and I assume you do) you have a final payment due, this will make a difference to the point at which you can 'VT' the agreement.
Officially, this doesn't go against you because you are exercising your Statutory rights but it will appear on a credit file and who knows what another finance company's underwriters will think. It is probably a good idea to try and do the two (VT & purchase new car) simultaneously so the VT slips under the radar of your new Finance house.
You gotta tie yourself to the mast my friend, and the storm will end.