Aren't we off-course.
The creditor is UKPC, not Skoda.
I cannot find anything in Skoda's correspondence which suggests they'll make any financial demands upon you other than they receive a 'second notification'.
But IMO you have no reason to think they will because:
UKPC have sent you a NTH;
And a Final Demand;
And an unseen letter(from a 'debt collector').
IMO, ignore Skoda* as regards the NTH, they're a distraction from what you should be doing which is appealing/writing to UKPC.
Apparently the UKPC we site won't let you appeal.
None the less, you should write to them and appeal.
Why?
Because it's what a normal motorist would do who has taken the time to establish the relative legal positions of the creditor and hirer and discovered that the creditor may not legally pursue the hirer of the car as hirer. The hirer then should communicate this to the creditor at the earliest possible opportunity. You can't do this online, so write to them.
In effect, the hirer would be setting out their cast-iron defence to prevent the creditor incurring unnecessary and irrecoverable costs by continuing to pursue the matter.
The legal position as I see it:
Failure to provide the mandatory docs under para. 14 to Schedule 4;
Failure to state correct practically all the mandatory periods and conditions applicable under para. 4 as regards having the right to enforce against the hirer.
*-if Skoda do write, then come back.
**- read para. 4 and see what a NTH should contain:
https://www.legislation.gov.uk/ukpga/2012/9/schedule/4/enacted