Mercedes-AMG A 45 S (W177)
Why 6.3: The most powerful series-production 2.0 four ever, torque-vectored to a fault — mighty and clinical in equal measure. Owners use the pace more than the drift mode, and the involvement number reflects a car that impresses more than it converses.
Layout
Natural habitat
Ride comfort
Sound
The M139 is the hardest-working production four made, revving to 7,200 rpm with a metallic, motorsport-flavoured edge and proper overrun bangs. But it is heavily turbocharged and openly augmented through the speakers, so the character is not all coming from the engine.
4-cylinder · turbocharged · 7,200 rpm redline · rated 5.5 / 10 for engine sound
Market value
Median asking price, good condition · €59k (2020) → €38k (2026), trending down · illustrative data
Child seats · ISOFIX
Two ISOFIX anchors on the outer rear seats, standard equipment on the current A-Class hatch.
No ISOFIX on the front passenger seat.
Mercedes A-Class (W177) / shared-platform GLA (H247) ISOFIX rear-seat fitting pattern (owner-community sourced, not manufacturer documentation)
The long version
The A 45 S sells to people who want maximum weaponry in minimum footprint and no interest in explaining themselves at the golf club. They track it occasionally — the cooling and brakes genuinely hold up — but mostly it does autobahn sprints and school runs with launch control saved for guests. The M139 engine is the ownership hook: hand-assembled, absurdly stressed, and the reason resale holds better than the A 35. Never sold in the US in any body, it is textbook Forbidden Fruit.