The genuine Fiat one is perfect - it has a 2cm high lip all the way round so contains any spillages. Also, I only spotted this the other day: I'd wondered why it had an 'odd shape' at the back right corner -- turns out this forms a perfect gap to slot a warning triangle into
There are several 'look alike' out there but generally they are just a flat piece of rubber (but still cut to that odd shape - pointless as they don't have the raised section to hold the triangle!)
I bought mine from a Fiat dealer, but via an advert on eBay - half price.
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