What have you found is a good iPhone app or web based app for logging maintenance/mod/care/etc for your vehicles? Since you are essentially slowly building a database, optimally you will want to be able to sort/search/etc. There are many out there, just wondering what you like.
I have one of those four way file folders with all the dealer reciepts, plus everything when I bought her, fastened to the proper place. After warrenty I'll think of some type of log, maybe Excel. Jim
When I ordered the car, I got a Moleskine notebook and documented the process. It then became my maintenance log, event notebook and gas log. I cant imagine an app that would be more handy and would be as easy to transfer to future possible owners.