As a monthly check-up, I'm updating my car value here. I drove quite a lot last month and my odometer now reads 35,400, or 1,300 miles for the last 30 days.
Here is the valuation compared to my first checkup back in October.
Trade-In Value: $11,353 (October = $11,711, Change = $358)
Private Party: $12,864 (October = $13,172, Change = $308)
Dealer Retail: $14,514 (October = $14,784, Change = $270)
Average Trade-In: $10,275 (October = $10,625, Change = $350)
Average Retail: $12,325 (October = $12,775, Change = $450)
It appears that the monthly depreciation of my Camry is very mind, averaging barely more than $100 per month with 1,000 miles/month usage. So it seems reasonable for me to depreciate the car by $150 per month in my accounting rules.