All of the hitches you referenced have about the same dimensions. We haven't had the chance to install any of them so while I can't give you the exact dimensions you are looking for I can help you determine it.
From the mounting surface of all of the hitches down to the bottom of the hitch opening the hitches measure 9-1/2 inches. If you measure from the frame of your vehicle down 9-1/2 inches that is where the hitch will sit. From that point you can measure to the ground and you will... view full answer...
The Swagman XTC-2, part # S64670 can handle wheels between 20 and 29 inches, so your bike will fit fine. The rack is limited to 2.5 inch wide wheels. view full answer...
I do have some information that will help us determine the ground clearance you can expect with the Curt Class I Trailer Hitch, # C11372, on your 2008 Lexus IS 350, however, we have not had the chance to install this hitch on that vehicle yet, so we do not have an exact measurement.
I can tell you that the overall height of this hitch is 9-3/4 inches (see photos). If you measure from the bottom of your vehicle frame rails, just above the muffler, 9-3/4 inches toward the ground, you will... view full answer...