The maxim "less is more" does not quite apply to coupes. These sporty cars, which command a premium price yet have fewer doors and less room, are better described as "less for more".
But to evaluate coupes this way would be failing to see the forest for the trees.
Coupes are about living the high life in the fast lane and you cannot really put a price tag on style, performance and that feel-good factor they evoke.
For instance, they turn heads.
Love it or hate it, the BMW 420i Coupe's controversial kidney grille will get you noticed. It is a big nose - there is no other way to put it - but its size and verticality are balanced by slim headlights with a lateral emphasis, making the overall facial composition appear not as objectionable.
The side profile of the 4-series is where sexy meets athletic. Think svelte silhouette, chiselled flanks and sweeping roofline. The rear is even more gawk-worthy with its beefy haunches, darkened taillights and black diffuser.
On the other hand and despite a second-generation facelift, the Audi A5 Coupe 2.0 is starting to look its age. Its front end alludes to classic sports car proportions, but its styling is more understated - like a buttoned-down suit compared with the BMW's more flamboyant attire.
In pulling off an inspiring cockpit design that is expected of a coupe, the 4 has sacrificed some visual clarity.
Both the BMW and Audi have a 12.3-inch digital instrument cluster behind the steering wheel, but the A5 presents the information more legibly than the 4's over-stylised graphics.
It is a shame that Audi lost the rotary controller, which is more user-friendly than a touchscreen on the move. What it has gained, though, is a useful cubby for odds and ends.
BMW's Intelligent Personal Assistant, which lives up to its name, scores brownie points. The voice recognition system, summoned by uttering "Hey BMW", processes commands more accurately and quickly, Singlish accent notwithstanding, than the Audi's Multi Media Interface does.
AUDI A5 COUPE 2.0 TFSI S TRONIC
PRICE: $222,200 with COE
ENGINE: 1,984cc 16-valve inline-4 turbocharged
TRANSMISSION: Seven-speed dual-clutch with paddle shift
POWER: 150bhp at 4,000rpm
TORQUE: 270Nm at 1,300-3,850rpm
0-100KMH: 8.9 seconds
TOP SPEED: 210kmh
FUEL CONSUMPTION: 6.2 litres/100km
AGENT: Premium Automobiles
BMW 420i COUPE M SPORT
PRICE: $242,888 with COE
ENGINE: 1,998cc 16-valve inline-4 turbocharged
TRANSMISSION: Eight-speed automatic with paddle shift
POWER: 184bhp at 5,000rpm
TORQUE: 300Nm at 1,350-4,000rpm
0-100KMH: 7.5 seconds
TOP SPEED: 240kmh
FUEL CONSUMPTION: 5.8 litres/100km
AGENT: Performance Motors
Practical considerations may not usually be at the top of a coupe buyer's list, but a practical two-door definitely augurs well.
The rear of the BMW is easier to access, thanks to front seats which slide forward and downward. And with a slightly longer wheelbase, it has more knee room back there. But the Audi has more headroom.
Both have split-fold seats, so it is possible to bring that Ikea flat-pack carton home yourself. At 450 litres and 440 litres respectively, the Audi and BMW have similar boot capacities, but loading up the latter will be less back-breaking - thanks to its lower height, wider boot aperture and automatic tailgate.
Behind the wheel, the odds are stacked in the 4's favour. The extra 34hp and 30Nm over the A5 is perceptible when you mash the pedal, even in Comfort mode.
In contrast, the Audi is best driven in Dynamic mode to compensate for its weedier engine.
While the 4 may be quicker from the get-go, it is around corners that the rear-wheel-drive really proves its mettle. It is next to none in terms of body control, balance and grip.
In comparison, the front-driven A5's desire to hustle feels less enthusiastic, like a reluctant partner being ushered onto the dance floor.
However, it glides along with absolute ease and composure. It is a car best experienced stirred, not shaken - complemented by a more forgiving suspension compared with the 4's M Sport springs which ensure no bump or pothole goes unnoticed.
Both cars wear 18-inch wheels. Over a three-day test-drive, the Audi averaged 10.4 litres/100km while the BMW achieved 9.8 litres/100km. The marginally lighter (by some 50kg) A5's higher fuel consumption could be due to it being driven predominantly in Dynamic mode.
The two German coupes put the pleasure back in driving, but it is the BMW that offers more joie de vivre.
The A5 exudes impeccable class with an air of sobriety, but it is the 4's dramatic looks that turn heads and set the pulse racing.
Even though the 4 costs over $20,000 more than the A5, it is worth considering forking out that extra money for a model which has more power, more features and better performance.
Plus, the BMW has nailed the elusive X-factor - something one cannot really measure in dollars and cents.