I've been in Czechy, Slovakia, Hungary, Croatia, Greece, Italy. Not counting passing-by.
Next year planning to visit UK, maybe I'll also take part in Złombol rally- the idea is to take 30+ years old communist car and drive through entire continent with banners on it, to earn money for charity purpose. You have to get to the finish line in time but the comeback is as long as you want, some travel that way for weeks.
They already went to Monte Carlo, Norkapp, Morocco etc. this year they're going to Spain, there will be over 200 teams at start. Great idea to travel on cheap, socialize with other teams, same time earning money for those in need and to get a perspective on things, that you don't need a plane or a new car to travel, you can take an old and cheap car that nobody wants to buy, give it a second life and get anywhere you want.