sub drive_type {
        my ( $self, $drive ) = @_;
        if ($drive) {
            unless ( $drive =~ /^(?:fwd|rwd|4wd)$/ ) {
                die "$drive not a valid drive type. Use fwd, rwd or 4wd\n";
            }
            $self->{'drive'} = $drive;
        }
        return $self->{'drive'};
    }

    sub body_type {
        my ( $self, $body ) = @_;
        if ($body) {
            unless ( $body =~ /^(?:sedan|wagon|coupe|hatch)$/ ) {
                die
"$body not a valid body type. Use sedan, wagon, coupe or hatch\n";
            }
            $self->{'body'} = $body;
        }
        return $self->{'body'};
    }

    sub engine_cap {
        my ( $self, $cap ) = @_;
        if ($cap) {
            $self->{'engine_cap'} = $cap;
        }
        return $self->{'engine_cap'};
    }