Parkers overall rating: 3.5 out of 5 3.5

Inside you know you are in a luxury saloon with the analogue clock in the dash and Japanese Ash wood trim giving pointers to a real premium feel. All the materials in the cabin are of high standard and the seats are suitably comfortable, although they could be more cosseting, especially in the S models, where enthusiastic drivers might need to feel more hemmed in.

There are myriad buttons and dials and while most of these are straightforward and intuitive, some do require a bit of working out.

The Infiniti M comfort levels are around the same as those in its luxury counterparts. There’s little noise intrusion from the engines apart from the slight disturbance you get from the diesel choice. On the motorway you can hear the diesel rumble a bit, but it's not unpleasant. Wind noise is almost non-existent while road noise only becomes an issue when you switch to the bigger 20-inch wheels found on the S model.

Finding a comfortable driving position is easy with the seat offering plenty of movement – although the electronic controls can be a little awkward to access – while the steering wheel is also reach- and height-adjustable. In the rear there is more than enough space for two adults. Legroom is impressive and offers a more comfortable space than that in the Mercedes-Benz E-Class.

There's enough headroom for taller passengers but the middle seat is best for small children only because the central tunnel restricts legroom.