Jim here again from Cost2Drive. We agree with Daniel that there are many costs associated with driving, and wear and tear can be a significant one, so we are actively working on providing this information in future versions of our site.
Regarding plane tickets – we do provide that information for routes over 200 miles. We display the cheapest fare found on kayak.com for the route specified. And we’d love to add Amtrak as well.
Thanks for the feedback.
Jim