[cinq]

Yes it is by design.
The Can Use vbGarage option simply allows that particular usergroup to be able to add a car profile or edit it.

If you want to restrict the viewing of car profiles or the main list page, you will need to add an if condition to the vbgarage.php file in the do=list section.
Something like this:

if ($permissions['genericpermissions'] & CANVBGARAGE) 
{ 
...view_car_profile_code_here.... 
}
else
{
print_no_permission(); 
}

Hope it helps