I don't keep records because my cars aren't nice enough to justify it. I've only ever owned one new car and with 160K on it now it has never needed anything major yet, so we don't have receipts for it. I am driving that thing til it dies so I don't give a crap about resale.
If I ever got anything new and fancy I might consider it. To answer the original question of why I don't? Not a priority.
