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...
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...