Glad to see another happy Insight owner around here!
Which size did you order the Potenza on tire rack? 165/65R14? If not they are not the right size.
Can you tell me where you found the underbody covers?
From your description I am sure you have a stick shift, am I right?
My Insight has 126k mi and the 144v battery was changed in 2007 by Honda.
Are you interested in ecomodding or just plain hypermiling?
Denis