Did you watch re-runs of Top Gear on Dave too? I am surprised given the popularity of the show that more people haven't gone for the car-seats-at-home option. You get head rests into the bargain, plus, if you need to re-upholster there are after market seat covers and even those bead things that people had in their cars then.

Essentially all these seats go for scrap so you could get the leather seats from a 7-series BMW to have a mega cool sofa at home complete with arm rest and cup-holders. With a few more bits of wood you could make some outer arm-rests. Heated/cooled seats could be nice too.

Maybe there is a 1990's sweet spot where the electronics aren't present so adjustment can be done with mechanical controls, as per your Astra option. A Transit Van could have particularly good pickings with the right vintage.

> Did you watch re-runs of Top Gear on Dave too?

Nah, I haven't watched any Top Gear. But the seat was just always so comfy in a way none of the seats in the never cars I've been in was. I think it is due to how the seat envelopes you, in a way reminiscent of race cars (which the Astra was not, by any stretch of imagination).

I think heated seats could be possible as well, I assume the required electronics and the protocols they speak for regulation should be rather simple. But given the seat is at home there is not that much need to heat it up :)

Something I'm planning on doing at some point, is to make a frame to attach the back seat of my Jeep on, to turn it into a "couch". It would be great for camping, or in the garage.

There was a company that sold a frame for doing just that, but they went out of business. Fortunately, you can still easily get all the attachment points/latches and such, and welding up some simple legs and whatnot isn't that hard.