Which car should i buy the Audi A4 or the BMW 325XI?

I am going to buy a car soon and love both Audi and BMW but i want a car that will look good and last me for the long run. Both cars would be black on black with the windows tinted. If you guys have any good recommendations for a car let me hear them also i herd the Cadillac CTS is also good let me know please help Thanks!