KBB.com 10 Best Certified Pre-Owned Luxury Cars Under $30,000. Only 26,683 Miles! Scores 29 Highway MPG and 20 City MPG! This Audi A5 delivers a Intercooled Turbo Premium Unleaded I-4 2.0 L/121 engine powering this Automatic transmission. Leather seating surfaces, Heated... via CarSoup