Thinking about getting a luxury car? If Audi then Audi A6 Sedan is probably on your shortlist. It’s sharp, loaded with tech, and built to impress.   But here's the real question:  Is it better than an older Audi model? And how does it stack up against the space and practicality of an SUV?   If you're stuck choosing between a pre-owned Audi, the latest Audi A6, or a luxury...