If you are within 3" then you will be fine, however if more than 3" I would recommend a drop hitch to bring it within 2".
You can get the hitch extension with the drop from Campingworld.com or
ETrailer.comWHat I would do is use the current bike attachment for the bikes and then buy a 4" drop for the car towing. This will put the car a bit further behind the bikes, and offer more space.
What I DID is install dual 2" receivers on my motorhome hitch. That way I can install a bike hitch on both sides of my motorhome and leave the center one for my car. . . I have a bike rack and a rack that holds my SACCO dog cart.
Have fun camping!
Fred.