The 2007 Cadillac XLR is available as a 2-door, 2-seat convertible. Starting at $78,335, the 2007 Cadillac XLR Base is powered by a 4.6L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 27-mpg on the highway. The top of the line 2007 Cadillac XLR Platinum Edition, priced at $84,160, is powered by a 4.6L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 27-mpg on the highway.