There's all sorts of differences, the SE is the top spec for those years (though you might find the odd Executive model). Thing is, that all sorts of options and packs were available so ideally you need to lay your hands on a brochure covering those years. But, buying secondhand over a couple of years old there won't be much difference in cost - go for the best you find. Check out the Volvo secondhand car site, the listings there may help you idenitfy some of the variations available. Main advice, is do not buy anything that shows any sign of warning messages or lights regradless of what the seller might tell you! PS: you posted in the 2007 model year on forum.