I put a car parking ticket on the dashboard where it meets the windscreen. Unknown to me there is a gap between both. Where would I be able to retrieve ticket, where does the gap feed to?

That's what the little plastic clip on the windscreen is for..

 

I have dropped stuff down there before and never retrieved it..  Then again it was never anything that needed retrieving, so I left it as opposed to take the dashboard apart for something.

 

I don't think it comes out anywhere easily obtainable.  I might be wrong - and hopefully someone will correct me to enable you to get the ticket back out.

Have you tried a piece of a4 paper with double sided tape stuck to one side? Rub along a carpet first so it's not completely sticky otherwise you may struggle to stick it down the gap.

That's how I retrieved things from an old car. There was a gap but it didn't go far but not sure on the octavia how deep it is or whether it does stop.

Just realized I've put this in wrong section. Ooops

I've done this and retrieved it by folding a bigger bit of paper in two and just dredging for a few mins and usually eventually see an edge if the ticket which you can carefully nab with a fingernail.

Sticky tape idea above sounds good.

I don't think anything will be retrievable anywhere else.

I would just buy a new parking ticket

Yeh, the lost one will have expired by now.

JKW