I have always thought that our government's tax policy should be driven by its positive impact on economic growth and that it should not be used for social engineering. If tax policy successfully increases economic growth, economic opportunity increases. Economic opportunity is the best way for individuals to progress from one socioeconomic status to the next.
A recent Tax Court case (Powell, TC Memo. 2016-111) reinforces the importance of keeping a detailed mileage log to support your business deductions. In this case, a taxpayer used his personal vehicle in his marketing business. He kept a detailed log with the exact miles driven, destination and purpose for some activities.