No idea.
Rear wheel drive so presumably rear engined - is that a carburettor intake behind the driver's head.
The body looks quite professional so could the basis be a proprietary kit for converting a VW into a 'beach buggy'? Being a two seater body bears this out. But it looks as if it may have a radiator.
Autocross, or grass track racing, specials were very much a case of adapt what you had. I have seen pictures of an ex-Formula 1 Lotus 18 chassis being re-engined and forming the basis of an autocross car