What I use is Quicken, not only do I use it to keep track of our checking and savings accounts, but all trucks, cars, and toys.
What I do is set-up an account for each (Dodge 3500 or Raptor) I just name the account after what ever it is, this makes it very easy to use. Then enter every transaction for that account like it is a check, the mileage being the check number. That way the mileage is always included in the update. I have tracked every car, truck, trailer, ATV, everything that way for the last 10-12 years. My Dodge has very transaction since it was delivered to me, that is every fuel fill-up, oil change, replacement part, accessory or repair since 10-14-96. I do this on all the vehicles, It takes very little time and It's a great tool for information latter on. The sad part is it also reminds you of exactly how much money you have invested in that vehicle. My last dragster I sold to a guy in California also had the same detailed report of all parts used, complete with name, part number, price, and quanity. The info helped me get a better price and also made for a fast sell. I listed the add on E-bay and sold it two days later for the Buy Now price. The detailed record keeping sealed the deal, I was able to fax a copy of the records to the buyer for him to see, once he seen all that was done and what parts I used, the deal was done.
I like the ability to track changes in mileage after certain parts are added. It is also nice to be able to look back and see all that was done, I would forget half of it with out it being written down. I hope this does look like it takes alot of time? It don't. The Quicken program makes it very easy, and that is the key to book keeping, accurate and easy to use. I even track each remote controlled car or truck we have, T-max,sport-max what ever, it's great.