Mistake. Thirty seconds of wheel-time in the new CLS 55 AMG was all it took to understand that this is the AMG hotrod we should have compared with BMW’s new M5. Not that a CLS super-saloon was on hand three weeks ago (Autocar, 21 September) but, with the benefit of all-knowing hindsight, the far more sporting CLS would give BMW’s new icon a tougher fight. No, we’re not saying CLS AMG would triumph over M5 – that verdict must wait for another comparison – but the fight would be closer, more compelling.

Judged as a sporting saloon, the CLS 55 AMG feels quite different (and superior to) the E 55. Ironic this, for it is their very commonality under the sheet metal that permits the AMG version to arrive just four weeks after the launch of the regular 350 V6 and 500 V8 CLSs, though all three versions go on sale simultaneously in the UK, early next spring. Normally, the gap between Merc and AMG versions is at least six months.

Just goes to show what can be achieved by fine-tuning the chassis. The key to the CLS’s more fluent handling is the 10 per cent quicker steering rack (not surprisingly, it also becomes standard on the E 55 from November production), fitted to all variants. For the CLS, AMG stiffened the rack’s mounting bushes to add further precision to the helm. Mercedes’ Airmatic suspension is standard on the CLS 55, the ride height set 10mm lower. To further emphasise the low-slung coupé-like styling, the test car’s new twin five-spoke 19-inch alloys (18s are standard) bulge out to fill every millimetre of the wheelarches. Can’t wait to see LA’s first blinged CLS 55 on 22-inch chrome rims.