Besides the seat itself, which others have correct said the comfort isn't just determine by how soft or hard the seat is, but also:

1. The actual ride quality and handling abilities of the car, both dependent upon several factors, such as:

• The vehicle type (SUVs will generally not handle as well as hatches and saloons which have a lower centre of gravity and possibly weigh less);
• The 'chassis' and suspension design, which can be in part dependent upon how the manufacturer believes it will be used, or in some cases, the suspension is tailored to a specific country (road quality), as well as cost or competence of designers;
• Some manufacturers compensate for not-so-good designs by firming up the suspension and fitting wider, low-profile tyres to get 'better' handling ability, but often at the expense of ride quality and the durability of the suspension parts.

2. The driving position, which is as much dependent upon the physical attributes of the driver (height, arm and leg reach, flexibility of the back, etc) and their preferences for how they sit (more upright or not) to get a good view of the road, as it is about the ergonomics of the seat, pedal / steering wheel position and how adjustable the latter is. With SUVs, for example, you often appear to need a more upright driving position than hatches and saloons

In my old 90s Micra, I experienced significant back problems but only after changing jobs, because I changed from a shortish (distance) local route at 30mph and less to a 20 mile route on much faster roads, including winding country lanes.

After spending quite a bit on chiropractors, a colleague gave me a copy of the 'seating ergonomics' part of his company car's manual. I discovered that my seating position was one click on the rack (about 1/2in) too far from the pedals and steering wheel (which couldn't be adjusted for reach), and within a week, all the pain was gone and never returned.

Similarly the setting for the lumbar support (if it has one) can make a big difference, and whether the car is used by multiple drivers - having memory seats is useful in such circumstances rather than having to either keep manually re-adjusting or accept a (bad) compromise set-up - which can be very bad if the drivers are physically very different.

With one problem solved (and this method of checking applies to any subsequent car I've driven), then it's as ORB says, being able to get a long enough time in the car when on the move (after getting the seating position right) is key.

Even the ergonomics of all the centre console area can make a difference - not having to reach or fiddle - it all adds or takes away from the quality of the driving experience.

3. A lumbering beast with a soft, but wallowy ride can be just as uncomfortable as a sporty car that 'runs on rails', just for different reasons - how you use the car, which needs to take into account the type and quality of roads you mainly drive on, must also be considered.

The seats need to not only be comfortable for you but also for your wife. Happy wife, happy life.

Long time ago. when I was having trouble with neck vertebrae that I'd damaged in the army, I was recommended to get a Citroen DS or equivalent.

I suppose this was down to the suspension rather than the seats, same reason I believe they were used as Outside Broadcast camera cars.

Didn't do it cos too stingy, though the DS is/was a very impressive car

I'm sure part of the difficulty in designing a comfy seat is the fact that people come not only in different shapes and sizes, but different proportions. My daughter is short, mostly because of short legs, so the fore-and-aft length of a car seat is important for her. And then there are those drivers unfortunate enough to have spinal problems.

To me, the silly thing is that makers can produce a seat which gets universal acclaim for comfort, but when that model is superseded the designers go back to a blank drawing board and come up with something worse. All versions of the Pug 205 had good seats (mine still does) but the only 206 I have owned became impossible to live with after about an hour's drive. Swapped it for a 306 Meridian and never looked back.

A former colleague of mine owned a 206 and despite the car itself being decent in performance terms, he never liked the driving position. If I recall correctly, it was one of those cars that had significantly offset pedals.

I learned in a 205 (1.9 diesel) and I found it comfortable, and one I could do the 'proper' look over your shoulder reversing manoeuvre without it giving me a bad back / sore neck every time. Not so on my old 90s Micra, but then for both those cars, parking was never difficult compared to modern ones due to the much larger windows than today's.

After over 60 years of motoring I’ve struck on a car which suits my driving position.

Its A RAV 4 Mk 2 which I can adjust the seats to give me perfect support , Great all round vision which you don’t get with modern cars because of safety considerations , so no stretching or straining to see the proximity of obstacles etc.

Downside bumpy ride which you would expect from a mild off roader.

"Never do anything standing that you can do sitting, or anything sitting that you can do lying down".

Perhaps this may not be the forum to develop this line of thought ? :-)

One thing that has gone downhill relating to comfort is ride quality. Everything seems designed to cope with track day driving,

Exactly! My Sportage suspension is very firm - one negative among some other positive things about the car. Every pothole can be felt in the cabin.

IMHO cars like JLR, French brands are more comfortable compared to other brands. So it is an irony that unreliable cars are more comfortable in general.

One thing that has gone downhill relating to comfort is ride quality. Everything seems designed to cope with track day driving, in order to gain positive platitudes from the motoring press no doubt. A recent shot of a Mk I Renault Laguna reminded me of how poorly most modern cars ride. If I want a track day car or a hot hatch I’ll buy one, I’m not looking for sharp cornering on a family wagon. Give me a 90’s executive or family car any day. Peugeot 406, Citroen Xantia, Renault Laguna Mk I, Safrane, Ford Granada, Vauxhall Carlton etc etc.

I doubt I would even notice most potholes if I was driving my old '84 Granada. I wouldn't want to go back to that fuel consumption at todays prices though.