What you do is get in first !
I had a similar problem a few years ago and what I did was ring the police ASAP.Give a description of this road rager and a formal complaint,so if the guy rings the police YOU got in first and they ask him to come to the police station to answer some questions LOL
It works like a charm.
Astronomy is my interest,Here is a pic from one of the boys last night from a back yard telescope.Good one Horus
http://www.astromart.com/forumphotos/107323.jpg
Here is some independant oil test results. All BS aside,the only way to test engine wear is to test the used oil for particulates. Obviously if the Fe & Al figures are high the more wear you are getting.
http://planetsoarer.com/OilAnalysis/OilAnalysis.htm
RW testers are liable in court if you or someone else is hurt ,or in any accident if the car is found to be un road worthy. Accident insurance apraisers do check.
It is more difficult now.