[Mondaveo]

Seat Cover: I don't know if it's ideal, but I use a bench seat cover by Kurgo (it's a US brand marketed for dogs). I had a cheapie previously which disintegrated, so I went for this as it seems to be better quality. The size is spot on for the back seat of the MC, and it has multiple clips and straps to keep it secured (under seat, behind seat, over headrests and under backrest). Unfortunately, even with all these straps I still have problems with it sagging at the top and folding over at the corners. Also the velcro covers for the seatbelt buckle openings just get in the way, but the centre storage pocket is neat and it's definitely durable.

Heated seats: Can't say definitively for MD, but in the MC the power connectors are fairly easily accessible under the front seats and by lifting up the rear seat base. It should be a simple matter to disconnect them.

Make sure you share a pic once you have the car!