Modern Vespa

Vespa GTS metal mudguard

GTS mudguards are plastic - end of.

I've not heard of metal ones, if they exist at all they'll be aftermarket. Why would you want one?

Zelioni do a nice one for that cut down look..

all i could find

FYI There's also carbon fibre (real) ones available

But isn´t steel right op your alley

Anyway, back to the OT, there is plenty ´universal´ stuff available for beer money.
The one below is RVS for 45 USD.

Isn't that what most of us call a fender, rather than a mud guard?

New to me. ´Fender´ is more related to a car. The Zelioni is simply a mudguard.

Most of you in the US perhaps. Most in the UK would call it a mudguard.

Divided by a common language?

It is a PITA to remove the original...

I'd call it an ineffectual mudguard - ain't gonna stop a lot

So true. Which is why the aftermarket mudflaps sell quite well! Plus thick protective plastic on the body just behind.

https://www.ebay.co.uk/itm/155114552978 <<< silly price example...

Where have I been - I also thought they were called fenders like Dooglas.

I did an online search - sure as heck, the images are of bicycles/motorcycle mudguards.

I guess this correct nomenclature did not penetrate this far to Minnesota. It is so darn cold here, whole groups of people and words just won't come here.

I did an unofficial survey of five of my fellow employees at work. All five called them fenders. Further, mudguards or flaps are what hangs behind truck and car tires to prevent splash up.

That is the latest from Lake Wobegon Minnesota.

Bob Copeland

Look up fender too

More seriously I think the difference is mostly cultural as US youths start/grew/grow up with four wheels. We in Europe generally with two.

I don't disagree that the difference is mostly cultural, but I don't believe it is linked to your association with two or four wheeled vehicles. I had my own scooter at 15 and have owned one or more scooters or motorcycles throughout my life. It was several years before I owned a car. I acknowledge Jim's point that this may well represent only US usage. Among me and my riding friends, the metal or rigid plastic thingy that prevents water from being thrown in your face or up your back is usually called a fender. The rubber or plastic thingy that you can attach to the front or rear fender to extend coverage is usually called a mud flap or sometimes a splash guard.

https://www.scooterworks.com/collections/mudflaps

Fender?

That's a guitar

Same in the UK - but mudguard is the bit over the wheel for bicycles and m/cs. That's exactly what it does on a bicycle - no fending done!

No, evidently not the same as in the UK. You must not have looked at my example of "mudguards" for sale by Scooterworks specifically for motor scooters. Or to beat a dead horse, here is one of many links to bicycle accessory suppliers in the US who sell "bicycle fenders". Different use of words in the two countries.

https://www.competitivecyclist.com/cat/bike-fenders?

https://www.instagram.com/reel/DCtlA97PgmX/?igsh=MzRlODBiNWFlZA==

Nice pointer to the origins of the word ´fender´ which apparently evolved in a broader direction in the US whereas this side of the ocean has the mud guards still doing thát.

´We´ have mud flaps too btw Dooglas. It´s the flapping things extending the mud guard on any vehicle. We usually call them just like that.
If I were still living in NW Europe I would fit one both front and rear on the daily Vespa.
Front to guard the scoot from more muck; rear is more sociable for those behind.

p.s. I am not a native speaker of either English version. More an independent observer schooled in both.