Another Specific Example
This post caught my attention since I just sold my 4 cylinder 06 Accord to go car lite (wife still has a car). I sold it to a family member, so I may have gotten more for it selling to another party. If my negotiation skills were as awesome as the OP, my numbers would be lower, but here is my best guess at actual costs. Assumptions were $2.85 a gallon and 25 mpg. Length of ownership was 5.5 years, and purchased new.
Car Purchase Price 16000
Sell Price 8000
Net Car Cost 8000
Insurance 2695
Registration 250
Inspection 300
2 Sets of Tires/Oil Changes 1500
Gas for 75000 miles 8550
Total Car Cost $21,295
Monthly Cost $323
If I would have sold the car for 16000, my monthly cost would be $201, a bit closer to the OP's numbers.