I have a set that came with my Caravelle - they're not great tbh, maybe if you only used them a few times a year they'd be OK.
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The middle and rear window ones are ok, they use the pull up blinds and hook over the top:
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The front side windows are pop up tent-alike, they're meant to sit inside the recess.
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The front and rear use tent poles and then hook into the trim on the rear, and just sit in the window frame somehow for the front.
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Tbh if you don't want to make any holes then these might be a good option, with practice I'm sure you could get them up in less than, ooh... 30 minutes?!
I put them in once and then packed them away again. They're not blackout but they do reduce the light by a decent amount. I'll get some pics tomorrow in the daylight.
I'll be installing some van-x Caravelle curtains in the next few months, along with a cab divider curtain. That and a windscreen cover for longer stays will be the perfect solution.
Edit: holy **** there's a set on eBay and they're asking £400!

they can't be worth that, surely?!