I, among others, are quite fluent in Computer. Writing such a program would not be all that involved.
So, start posting with your ideas and desires. Try to be reasonably clear, though. Vague, ambiguous concepts are kind-of hard to translate into code.
To start, it sounds like what you want is quite similar to an appointment program, but based on mileage as well as time.
So, for someone who wants to change his oil every 5000 miles or 3 months, he should be able to specify the maintenance item (Oil Change) and the repeat frequency (3 months and 5000 miles). And when he enters the oil change info after he's performed it, the program should automatically adjust the repeat schedule.
Also, the program should emit a warning 7 days or 250 miles in advance of the scheduled maintenance. "But," you ask, "how do it know how many miles have elapsed?" It doesn't. It can only extrapolate from the mileage previously entered and making a best-guess as to when the mileage will catch up.
Ideally, this should be on a Palm organizer. Even more ideally, the vehicle should have an infra-red interface that ltransmits (beams) the current mileage to the owner's Palm when that Palm asks for it.
Hmmm..... A Palm program that has, among others, a "Re-fuel" button that gets the mileage from the truck, gets the gallons and dollars from the user, then sends a 'reset trip odo' message to the PCM/instrument panel.
Anyway. What are your thoughts and ideas?
Fest3er