If you're going to buy a new car, do it soon.

Discounts are the great unknown if the car industry – beyond the fact that we all know all the mainstream brands do them, and that the salesmen deny any knowledge of them.

Beyond www.whatcar.com's excellent Target Price service, which uses mystery shoppers to ascertain the most you should pay for a new car, information is scarce.

In recent weeks, though, I've been scouting around, and it's become abundantly clear that there has never been a better time to negotiate, especially if you are willing to buy from among the brands that the SMMT's sales figures earlier this week made clear are struggling.

Key to negotiating a keen deal is identifying a European manufacturer that is making more cars than it can sell. At the moment, the favoured market for pumping out the overstock of cars is Britain, because the pound is so strong against the euro. Put simply, a car sold here is worth more – or, if you haggle hard, can be discounted by the manufacturer with less pain.

Beyond that, shop for the more unpopular cars, trims or engines. The more offbeat your choice, the more desperate they'll be to shift it. Large petrol-powered SUV, anyone?

Insiders tell me that discounts are running up to 20 per cent more in the buyer's favour year on year, as the pound stands firm against the euro and increasingly desperate manufacturers ask their UK subsidiaries to shift more metal.

Quite simply, there has never been a better time to buy. But will you? And if do, what will it be?