I was tempted. Bought two at £9.99 each. Fitted one yesterday, usual elastic and hooks. Bus seats are bit small for back straps. Tried it out, quite warm underneath and up the seat back this morning, ended up having to turn it off. 36 watts apparently or 3 amperes in old money.
Seat base has 4 elastic straps and hooks that would easily find a spring underneath. The back has 2 webbing straps that clip to a tag that pulls through the gap between the seat back and seat base. So nothing requires a seat to have any particular width apart from being at least as wide as a pre 1975 seat. Should fit. May need to extend cigar lighter cable.. on my bus there is a convenient leisure socket up by my left shoulder, on the Devon "wardrobe" cupboard.
The only time I sat in a car with heated seats I had the feeli g I had just wet myself. (I hadn't...)
I bought a pair last year and they worked superbly, only issue I had was the adaptor I had to be able to use two blew a fuse with both on so we took it in turns to be warmed. Didn’t bother with the straps and just used them like thin cushions. Ozziedog,,,,,,,well worth the couple of Bob they cost
I could tell you a story about abusing the effectiveness of alli diet pills after a Saturday Chinese and a Sunday dinner - made for an expensive Monday morning drive to work... but I won’t