Powered sliding door

I don't know specifically about the Boxer, but on the T5 there were two factory options: powered latching, and fully powered opening/closing.

The latter is pretty complex, requiring a motor, cables, position sensors, anti-trap sensors, roll-back and (of course) a computerised controller to make it all work. When it goes wrong it's a bit of a mare to get fixed, and parts are very expensive.

The power latching system is much simpler, though it still requires a different motorised latch, trap sensors and a (simpler) control module. It seldom seems to go wrong (though that may be because it was a fairly expensive option that not many people chose).

Which type were you thinking of?

I guess the first thing to do would be to research and find out what door options were offered by Peugeot from the factory for your model. You can then find out more about whether someone would retro-fit for you.

But be warned - all of the main car manufacturers have their wiring looms made to ordered spec these days, so the wiring for any factory options you don't select won't be in the vehicle. If I had to guess at cost to install for fully powered on a T5, I would start with a figure around £4-5k, using new original parts.

I doubt anyone makes an aftermarket kit and, even if they do, I wouldn't consider getting one, because I doubt it would be durable/reliable in the long term.