For the work I've done myself, I have all the receipts for the parts and I write down the miles I've done it and takes photos while I am doing it for my own documentation. I thought I was going to drive this car forever like I have for all my cars in the past.
Here is a longer blablabla version of the ad on Rennlist LOL
http://rennlist.com/forums/vehicle-marketplace/966498-fs-2003-porsche-boxster-s-ims-retrofit-done-all-records.html