Easy way to add wider window trim to the exterior of vinyl sided home?

What about decorative trim like what you use around doors or decorative moulding. You can adhere it with silicone or possibly Loctite.

Fix it on top of existing or extend existing.

Thanks for this suggestion. I’ll give this a try.

That's what I intend to do when I paint the outside of our doublewide. Using white 1 x 4s around the top and sides, and then put black shutters (also home made) on either side. It'll look really sharp.

Look into Architectural Exterior Foam. Amazing and sturdy stuff.

Several manufactures who even do custom work, online sites

Hadn’t thought of that. Thanks for the suggestion!