In general, I would say that /ford-transit-260-swb-85ps-low-roof is too long to be helpful to anyone. However, in YOUR case, I would probably stick with it - you need some way to differentiate the URLs of all the different types of car (I'm not sure you need van-for-sale on the end though - even you got bored and chopped that off!).

Having said that, you have other issues - such as that page redirecting to a non-canonical version of your homepage ...

Things I would sort out first: Make sure your HTML titles make it clear that the vehicles are for sale, make sure you use meaningful anchor text to link to your own pages (not 'more info'), add unique meta descriptions, add unique copy to each page. When a vehicle is sold, don't delete the page automate the process of adding "sold" to the page plus a list of current sales for "vehicles like this one".

But looking at your URLs like: http://www.zebravehicles.co.uk/vans/vehicle-leasing,-car-contract-hire,-nationwide-vehicles,-vansdirect,-low-cost-vans,-motorpoint.html I WOULD recommend changing them as that looks like a nighmare URL!!!! It's of no help to users or search engines ....

I think its a fair comment to say "every little" helps.

There is no single method to achieve SEO perfection, search friendly urls, meta data, H tags, alt tags, file names, file location folder names, keyword density, sitemaps so on and so forth all just adds up to making it clearer to both search engines and users what your site or page is about.

Matt Chatterley - im all for using the term 'natural language' URLs - good shout

This article has put my mind at rest, however does highlight the advantage so I will still implement them but no rush for them now.

Thanks