Modern Vespa

anyone know why some of the 946s have solo seat... and some double seat.... and if it has the double seat... can you remove the back section of the seat - and leave it as a solo seat?

I'm no expert, having never owned a 946, but I believe that all 946 models only come with a solo seat, on a single seat pan. Some versions of the 946 seem to have the cushion in two parts (the main front part and a small vestigial rear part) but they both rest on the same seat pan.

That leads me to believe that no, you cannot remove the second cushion.

If you are looking at something that genuinely looks like two people could fit on it (i.e. not a solo seat) could you post a link so we know what you're referring to?

There's a thread here on seat swap.
946 Bellissima seat install

It does look like there is a version with a two part seat.

Well spotted. I hadn't seen that version.