Well I would not even consider the TT since it is FWD and the slowest out of the packed. You are left with the Audi A5 and Corvette
Audi A5:
Pros:
-AWD is strandard
-2.0: TFSI (HP 211 Torque 258) OR 3.2L (HP:265 Torque: 245) More power than the 3.5L Mercedes -Engine
-Eco-Friendly and Efficient
-Great Acceleration (0-60 6.1 sec)
-The design - Quite simply a desirable coupé
-Lines and surfaces play with light and shadows
-The interior - The luxurious perfection of an Audi
-Ergonomic design and functionality
-Exclusive materials and Audi's typically superb build quality
-FSI - The high-tech engine with variable valve lift
-Key with a sharp memory
-Interior design a high-quality tactile experience
-Long wheelbase, short overhang
-The body - Generous and superlatively solid
-The equipment - Luxury class high-tech features
-LED strip of daytime running lights
-Sport Tuned Suspension
-Great Throttle Responsive
-0.29 Drag Coefficient which is better than a Porsche Turbo
-Can seat four adults comfortably
-18in Rims are great
-LSD
-Audi Name Plate
-DSG Transmission is great
-Racing Style Seats
-Rigid Chassis Gives better handling and safety
-High Quality Leather
-The design is the definition of a coupe
-Great Handling
-Steering Feel
-Dual Exhaust
-Audi was ranked #4 by JD Power for Performance and Design
Cons:
-Ride maybe harsh for some people
-Expensive, rare material used in engine=High Costs for repairs
Chevrolet Corvette:
-Blistering fast acceleration (0-60 4.6 sec)
-Sport Tuned Suspension
-19 in rims
-Wide Tire
-Racing Inspired Seats
-Great Throttle Response
-Responsive Steering
-Muscle Car design
-Classic Corvette design
-Great Handling
-185 Top Speed
-Quad Exhaust Make a Deep Exhaust Note
-RWD
Cons
-Harsh Ride
-Cheap Interior design
-Cheap Interior material
-Terrible Fuel Economy
-Only seats 2
-Power Tap Transmission is a little crude compared to European counterparts
-Less Bang for your buck
-Uncomfortable interior seats
-Leather was known to crack and rip
-High insurance
-Low HP For a 6.2L (438 hp)
-Very High Drag Coefficient
- Cheap Plastic use on Exterior
-Plasticky Interior
Your Best Choice is the Audi A5 but I do have a list of cars for Under 45,000 New and used that have better cars than these 2.