You would be a danger to society if you tried to replicate the feeling of a kart in a real car on the road.
I’ll assume you mean a real car that you can drive on a track. In that case, the answer is always Miata. Unless of course you have the money for an Ariel Atom or BAC Mono or something of that sort. But as far as smiles per dollar are concerned: Miata.
2010 Spirit [Birel] SP32 // SRS CR125 - Stock Honda [#08]
Hill Country Kart Club - New Braunfels, Texas - http://daledaugherty.wordpress.com/