One of the things that ends the cooling off period, as stated in the Motor Dealers and Chattel Auctioneers Act 2014 is:
"at any earlier time [than the cooling offer period is due to expire] the person contracting for the purchase of the vehicle takes physical possession of the vehicle for the a purpose other than -
(i) a vehicle inspection; or
(ii) a test drive."
There are two important aspects:
1. The point of time of taking possession; and
2. The intention at that point of time.
If you take possession of the vehicle and then, driving home with it, decide to take it for an inspection then that is too late. The moment possession is taken that's the end of the cooling off period. I don't think this is what you're meaning, but it's important to mention.
The other situation is if you intend to take it for an inspection. Then the cooling off period may not be ended. However, taking possession is a two part act: you have to accept possession, and the dealer needs to give up possession (It's a technical argument, but part of the reason why we lawyers exist).
'Inspection' and 'test drive' are clearly not an 'accept and keep' outcome - they're designed to obtain information about the car from a mechanic and your experience of the vehicle, respectively. They also imply that the dealer is aware that your intention in removing the vehicle from their dealership is to do so, and return it.
That is fundamentally different to giving the intention that you are taking the car as the conclusion of an offer to purchase. That implies that you have accepted the vehicle and do not require the testing via inspection/test drive.
In terms of demonstrating the difference between the two, the dealer would clearly be informed of whether you were taking it for a test drive or to a mechanic, because it would be expected that that very point would be discussed and arranged.
I also don't see the benefit in hiding the intention to get the vehicle inspected under the guise of accepting it.
