carrying capacity and long haul drives.

Personally I wouldn't bother with plywood in the back if it's just for the one trip. You don't gain anything other than neatness. I took the seats out 3 years ago and left it like that. I've never had a problem with using the floor!

A trailer is an easy way to increase carrying capacity. On a long trip like that I would be carrying a spare wheel and wheel bearings for it and the tools needed to change them. Also be aware speed limits are lower with a trailer. If you are buying a trailer, buy one that's a practical size e.g. can fit a bicycle, lawnmower, sofa etc. The little 3x3ft trailers carry barely anything yet you still have the same hassle of towing that you get with a bigger trailer. My 8x4 trailer is great behind the Jimny and I wouldn't hesitate using it on a trip such as yours.

Regarding roof bags, be aware that with anything that straps through the door seals it will wick a surprising amount of water in when it rains!

Whatever you choose to do, have a great trip. It sounds like quite an adventure!

Thanks for this. Good to speak to someone with experience of a trailer on a Jimny.

Your 8x4... do you mean the box is 8ft long by 4ft wide? Meaning the length including A frame would be about 10ft? Do you find this is manageable? And how tall is it? I'm bothered by the prospect of cross winds... the Jimny's a light vehicle and could presumably be easily affected.

Finally, do you have a max recommended towing weight to suggest? In theory I cold make any trailer very heavy, but I do only have a 1300cc engine...
Thanks.

Suzuki recommends 350kg or 450kg for trailer with brakes.

As someone who tows a small 750kg caravan it's no problem at that weight but if climbing long hills you'll be changing down a gear or two.
A trailer shouldn't be bothered by crosswinds as it is lower.
In the UK you can tow 1300 kgs with a braked trailer (350 unbraked) but some countries are much lower than this so I would check your local regulations but general EU regulations should allow you to tow whatever your local regs say
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I'd be more bothered about ferry costs as adding a trailer will certainly be more expensive so by choosing a certain size you may be able to just duck under a higher ticket price?

A lot of the trailers I've been looking at are 5ft tall. That's a significant face to present to a crosswind on an Alp. But presumably your caravan then discounts this as a problem, if you find it's ok...

Good point on lengths and ferries. I'll take a look.

Ah ok you're looking at a box or covered trailer then?
I'd certainly try and keep the weight down if you are going over the alps (not that I have) but as you say it's only 1300 cc and the Jimny will do it but you will be in the lower gears so 60/80 kph (or less) will be more like it on the hills.
My caravan will sit at 60mph (96kph) on the motorway but can easily sink down to 40mph (4th gear) on those long inclines.
You will also have the extra weight in the car itself so you'll be keeping company with the trucks.
Plenty of travellers have crossed Europe on push bikes/mopeds/scooters etc in the past and I'm sure the Jimny is up to it but not at motorway speeds.

Just one more thing re the trailer I presume your car is registered over there so do you need any documents for the trailer as some countries require them to be registered but in any case get one that has been EU approved and has a certificate or plate of conformity.
Don't forget a number plate as well as you won't get a foreign one made up over here.
We don't have to bother here with older (cheaper/home made) trailers as long as the lights work and the tyres are good but you may have problems if stopped.
The modern alloy style ones are ok but I would get a braked one considering the type of journey.