Definitely not an R8, and i'm pretty sure it's not a Simca 1000. I don't think it's Japanese either, the white steering wheel is not something any Jap car had in the mid 60s AFAIK. Also, it's LHD which means an impot, and Japanese imports only really took off in 67-68. looking at the styling it seems to be about 65-68. It would help to know what country you saw this in!
I love that people on this site can identify a homemade 1950s Lithuanian microcar, but no one (so far) can identify a major production car like this!