The alternative fuel debate powers on, with liquefied petroleum gas conversions at the fore. The problem with LPG (and compressed natural gas) vehicles is that they fit into two different categories – manufacturer conversions from the likes of Vauxhall and Volvo, offering factory-produced cars and then the aftermarket conversions. One of CAP's most frequently asked questions is what the effect these conversions have on used values.

The fact is, there's not a huge take-up of the manufacturers' own bi-fuel or LPG cars, which is probably not a bad thing for residual values. Those that are selling are making modest premiums, at best, over their petrol counterparts. But there's more concern over the aftermarket fits.

While there are several reputable, manufacturer approved conversion specialists around, stories of engine problems, quality of fitting, inability to carry out accident repairs and the overall safety of the vehicle are commonplace. All these concerns are having a negative effect on the values of LPG and bi-fuel cars, with many in the trade reluctant to even bid at all on them.

Alternative fuels will continue to be developed by the manufacturers over the next few years but hybrids such as the Honda Insight and Toyota Prius have hardly taken the market by storm and seem more of a toe in the water exercise rather than a strategy.

Development will no doubt take place – in particular with fuel cell technology – but we're concerned with the now, and caution is the watch word. Despite years of Government puff, used car buyers remain worried about where they can fill up with gas, about reliability and safety. Motorists remain less concerned about the many other issues that alternative fuels are supposed to solve.

Meanwhile, the quiet trade period anticipated for earlier in the month has passed without causing any great meltdown. Although there are a few more cars around, the big trade buyers are back out with their chequebooks, sourcing the two-to-four- year-old retailable stock, which is helping to keep the ball rolling along nicely for the time of year.

Nearly new stock is abundant, with some models affected by the supply issue more than others.

One example is the Ford Focus, where the trade is looking to force values down to a level more in line with the competition.

On the flip side the Vauxhall Vectra is finding an upturn in demand because it now looks such good value against the competition.