But in your scenario, if you're always rolling that equity over into your next car and you always get rid of your cars before 60k or 5 years, what's the advantage over leasing? Assuming you don't put any money down on a lease, you don't need any equity from the previous car. And it sounds like you're OK with almost always having a car payment. So what's stopping you from leasing a BMW/Lexus?
(not trying to contradict you BTW, it's just that lease vs. buy is a constant argument I have in my head, and I'm always curious to hear people's rationale)
The primary financial advantage of owning a car verses leasing a car is an implied longer holding period. A longer holding period implies less total depreciation. (A lease payment is calculated to pass 100% of the depreciation on to the lease holder for that lease period, plus profit.)
Most cars depreciate at a flat rate each year. It doesn't really change from year to year and is typically around 17% per year. Starting with a $30,000 car, this would be the value at the end of each year for a 6-year period:
• Start: $30,000
• End of Year1: $24,900
• End of Year2: $20,667
• End of Year3: $17,154
• End of Year 4:$14,237
• End of Year 5: $11,817
• End of Year 6: $9,808
Total Depreciation: $20,192
A three-year lease would look like:
• Start: $30,000
• End of Year1: $24,900
• End of Year2: $20,667
• End of Year3: $17,154
Total Depreciation: $12,846
PLUS other new lease for the next three years:
• Start: $30,000
• End of Year1: $24,900
• End of Year2: $20,667
• End of Year3: $17,154
Total Depreciation: $12,846
Total depreciation for two three-year leases would be $25,692 versus $20,192 if you held one car for same six year period. However if you bought a car and traded it in every three years, the depreciation would be the same.