The IRS has issued a reminder to individual taxpayers who are considering buying a new car that they have until Dec. 31 to take advantage of a tax break that may not be available in 2010. Taxpayers who buy a qualifying new motor vehicle after Feb. 16, 2009, can deduct the state or local sales or excise taxes they paid on the first $49,500 of the purchase price. Qualifying motor vehicles include new passenger automobiles, light trucks, motorcycles, and motor homes.