Short answer – as much as you like. Anything less than a full wrap is normally called a ‘partial wrap’.
Half Partial Wrap
Normally includes the entire rear of the vehicle and half way up the body and also includes a hood logo.
Three-quarters Partial Wrap
Includes the entire rear, most of the body of the vehicle and also includes a hood logo.
Full Wrap
Includes the entire surface of the vehicle except the roof – roof wrapping is additional.