Regarding your question about MPG, I believe that a lot of the numbers you see reported are either from very lucky individuals with exceptional cars, faulty odometers, or myth.

There was a thread a while ago on the Diesel Board about MPG, and GregS gave out a link to www.fueleconomy.gov. I checked to see what kind of MPG my 300TD-T was supposed to be getting, and my car is pretty much on the mark. BUT, if you compare my mileage to others around here, I'm missing out on 7-8 miles a gallon...

By the way, the fueleconomy website only goes back to 1985, so it may not be of any value to you.