Just curious how the Uber drivers handle taxes? Do they write-off the mileage and report that the car used for Uber was used for business part time?
I am not an Uber driver, but I would expect that Uber just gives you a 1099 for what they pay you. If you don't know what a 1099 - it's simply an IRS form that reports how much they paid you.
Uber won't take out any taxes. That's up to you to take care of.
They also don't write off anything for you. It's up to you to report your expenses when you file your taxes.
When you file your taxes, if you want to deduct your expenses, you will need to document what percentage of your miles driven were for business purposes. If 20% of your total miles driven was while driving for Uber - then you can deduct 20% of your gas, your insurance, 20% of the interest on your auto loan (if financed) and your maintenance.
Depending on your tax situation - you may not benefit by itemizing deductions though. For some people - the standard deduction is better.