Summer is not really the right time to visit Europe. Over priced, fully-packed with tourist & most-importantly it’s deserted during August. France, Italy & Spain are the best for road trips. You can either rent a car or use their superb train system. Last June I went to Spain, I started my trip in Madrid, then headed south by train to Seville, and from there I explored most of Andalucía cities like Malaga, Cadiz, & Cordoba.