As you might have already read in this week’s magazine, this Christmas and New Year promises to be a challengeing time to be in the motor trade, but also a great time to buy a new car.

The prospect of 20 per cent VAT has been bringing plenty of custom into showrooms, artificially inflating registration figures all autumn. But December’s historically a quieter month for new car sales, and if the weather stays as it is, it could be the perfect time to snap up a bargain new or good-as-new model.

And not just because of the slowdown in footfall. EU ‘Euro-V’ emissions law comes into effect on January 1st 2011, making it illegal for most dealers to register any new car that isn’t sufficiently clean of tailpipe to comply.

Most manufacturers have succeeded in updating their models with the latest engine technology this year, and so the biggest selling cars on the market – the Ford Fiestas, Vauxhall Astras and VW Polos of this world – won’t be affected. Others – importers like Mitsubishi and Subaru mainly – have been given extensions on the changeover, largely because their business depends on importing cars when the exchange rate is most favourable and holding them in storage, sometimes for up to year.

But some manufacturers have only just updated their models, and a few have yet to do so. And that means there will be bargains to be had, if you’re prepared to get out there and hunt for them.

Here’s an example: all UK stock of Honda’s Civic diesel, as Autocar understands it, must be registered or pre-registered before end-of-business on December 31st, simply because Honda never updated the car with a Euro-V-compliant engine. The car remains in production at Swindon for non-EU markets, so there’s a good chance that there’s plenty of stock still to clear.

Likewise, Toyota has only recently updated its Land Cruiser with a Euro-V engine, so there’s a good chance of a handsome deal on a stock example of that car.

Dealers who don’t push to register affected stock this month may be left with a glut of pre-registered cars to clear in the new year. Because dealer demonstrator cars have to be kept for 90 days in order for the registering dealer to qualify for a manufacturer discount, and because there are similar impositions on pre-registered cars processed through finance schemes, it could actually still be months before the tastiest deals appear. But appear they will, you can be sure.