BMW 4 Series Gran Coupe review

All 4 Series are in M Sport spec. That means a body kit with spoilerage, and firmed-up springs and dampers versus, say, a basic 3 Series saloon.

The 420i starts at £41,650. A lot for a 'base model' five-door hatch, but the equipment is solid: autobox, 18s, all-LED lighting, leather, reversing camera, online navigation, wireless phone mirroring. BIK is 36 per cent. Stepping up to a 430i adds just over £4k to the price but hardly harms consumption.

The Pro Edition Pack is available on most engines except the M440i xDrive where the kit is standard. It's just shy of £5k and you get among other things 19s, metallic paint, adaptive suspension, M Sport brakes and differential, and hi fi speakers.

Other option packs include a huge bundle of driving assistance and audio for £3,650.

Or from 420i to 420d is just over £2k, but BIK drops to 30 per cent and WLTP economy goes from 41.5 to 56.5. On the diesel, xDrive is only another £1,500-odd.

Finally the full-ticket M440i xDrive starts at £54,670, and CO2 is 181-193g/km depending on wheels.