re: Anyone in sales and have a car allowance/gas card?

I am a CPA, so I will throw this out there. Take it FWIW.

It sounds like you are getting 2 separate payments.

One in the form of a car allowance. I don't know the stipulations on what exactly this is - but this is probably taxable income. Like getting a bonus.

Two is a Corporate Gas Card, which sounds like it is directly paying for your gas only. The IRS allows you a standard mileage deduction of 55.5 cents per mile in 2012. My guess is that if you keep a log of your miles driven for work and the amount of money you charged to the Corporate Gas Card you should be able to come up with how many cents per mile the gas card paid for. You should be able to deduct the difference between 55.5 cents per mile and the amount that you just calculated as being covered by the Corporate Gas Card, as long as the unreimbursed portion is greater than 2% of your AGI and you itemize.