I'm currently developing a car classifieds site, to make the process easier for the user we want them to select their car by year, make and modal (European cars) which will automatically input most of their car specs for them (top speed, fuel type, transmission type etc). Everything I have found online provides incomplete data or is more for US modals. Where do the big companies such as autotrader.co.uk get their data from?
At my last job we used this service for our newspaper auto classifieds.
We used the edmunds one before switching to chrome.