Many thanks to Wee Smurf for the recommendation of the official Panda sun blinds!
I looked up the part number via Google and found them priced at £59.99 online but no descriptions other than the name "sun visor". Really, I wanted to know what I got for my money.
I then went to my nearest (v. unhelpful) Fiat parts dept who looked up the part number, £59.99 and item called "sun visor". They couldn't give me any more info and if I ordered the part then I had to pay for it and there was no refund if I got a sun visor rather than sun blind(s).
So I then went to the second nearest parts dept (Wentane in Stockton on Tees) who have been there for around 30 years. Really helpful parts man, Ian. He first of all pulled out a ring binder full of official Panda accessories catalogues - but sunblinds weren't in the catalogues. Then he looked up the part number - sun visor at £49.99. Ten minutes later he had found more info that suggested sun blinds rather than sun visor. If I ordered and it was the wrong thing, then I would have to pay a 10% handling charge to return them (i.e. £5). I ordered, he rang me three or four days later to say the part was in.
What I got was a nylon zipped bag with the Fiat logo on. Inside was a 6 part kit of sunblinds, some clips and printed fitting instructions.
The blinds for the rear quarter lights are a push fit. The pair of blinds for the hatchback have clips to fit them but mine have just been a push fit and haven't budged yet. The rear side windows use four clips with sticky tape on the back of them.
To see into the back now you have to virtually put your nose against the glass so they do the job I wanted (which was to prevent easy view of stuff in the back of the car when the seats are folded forward)
Again - thanks to Wee Smurf, the part number again is 46002920 and don't be afraid of the part being called a sun visor!