Just a tip that most of the coastal towns is the south (along the "sole") are new, pretty ugly and not worth visiting. The charming old towns are in the hills as the inhabitants stayed there for safety reasons until relatively-modern times.

As for autostradas in the south, be aware that they can be/are very narrow compared to U.S. standards (and have dense brush growing right in the narrow median to boot) are are often down to one lane.

It's kind of far away for 4 days/nights but Alberobello and Matara are worth visiting.