The more things change, the saying goes, the more they stay the same. Audi was quick to evoke its well-loved first-generation A4 sedan during the introduction of the 2015 A3 and S3. "It is a car Audi of America asked for," said A3 product manager Mark Fruechtnicht. Just how similar are these two compact sedans, 20 years apart? Take a look at our impromptu gallery to find out.