Handling
With its tighter turning radius, the Dodge Challenger is most certainly more agile than the Audi S5, something to consider if you do a lot of city driving; on the other hand, remember that a vehicle with a tight turning circle may feel a bit twitchy on the highway.
Drivetrain
The Audi S5's engine is significantly more massive than the Dodge's. Remember that more massive engines may use more gas than smaller ones.
The Dodge Challenger could learn a lesson or two from the Audi S5 with respect to torque.
Torque is the force that lets you accelerate quickly, and in this respect, the Audi S5 is significantly more powerful than the Dodge Challenger.
Utility
The Dodge will definitely prove handier than the Audi S5 for those of you with frequent child-cargo.
Convenience
The S5's fuel tank will need to be replenished more often than the unit in the Dodge Challenger.
Comfort
While the front cabin in the Dodge Challenger offers a bit more head room than the Audi S5, there frankly isn't much of a difference.
Dimensions
Your wallet will hurt more every time you fill up the Dodge Challenger than the Audi S5 because of its bigger tank.
The Audi S5 and the Dodge Challenger compete for the same parking spaces.
The Dodge Challenger's longer wheelbase will result in a smoother, more stable ride; on the other hand, the Audi S5 may give a sprier feel in daily traffic.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. The Dodge Challenger is significantly cheaper to get to the dealership than the Audi S5.
With respect to fuel economy, the Dodge Challenger bests the S5.
The Audi S5 doesn't pale in comparison to the Dodge with respect to fuel economy.
The S5 is tremendously more expensive than the Dodge Challenger in terms of MSRP.
Warranty
The basic after-sale protection that comes with the Dodge Challenger isn't quite as generous as the Audi S5's.