BMW Z4 M Coupé
Why 5.9: BMW welded a roof to the Z4 roadster and claimed two and a half times its torsional stiffness, then fitted the E46 M3's 3.2-litre S54 in full 338 hp tune with a six-speed manual and no automatic option at all. 4,275 were built in two years — fewer than the Z3 M Coupé that gets all the attention.
Layout
Natural habitat
Ride comfort
Sound
The same S54 straight-six as the E46 M3, hard and metallic to 8,000 rpm, and the closed shooting-brake shell resonates it more than a saloon does. Level with the M3 because it is the same engine, behind a slightly softer stock exhaust.
6-cylinder · naturally aspirated · 8,000 rpm redline · rated 8.0 / 10 for engine sound
Market value
Median asking price, good condition · €47k (2007) → €66k (2026), trending up · illustrative data
Child seats · ISOFIX
There aren't any — strict two-seater.
The only position there is, so makers of this era equip it: expect a passenger-airbag cut-off (key switch or occupant sensing) as standard, because there is no rear row to point children to. Whether the seat itself carries ISOFIX anchors is maker-specific — Porsche bundles them with its child-seat preparation, Ferrari sold them as an option, others are belt-mount only with the airbag off.
Derived from production years and seating layout, not a per-car source. ISOFIX was standardised as ISO 13216 in 1997, required on new EU model types from 2011 and on all new EU cars from 2014.
The long version
The Z3 M Coupé got the nickname and the cult; the Z4 M Coupé got the engineering. Wider track, a far stiffer shell, hydraulic steering BMW never asked a motor to help with, and the same S54 straight-six that made the E46 M3 what it was — 338 hp at 7,900 rpm and a redline at eight. It ran from 2006 to 2008 and stopped at 4,275 cars, 1,815 of which were sold in the United States, so this is a rare car that was never marketed as one. The ownership pattern follows the rarity: annual mileage is low, most are stored over winter, and a car that listed near $50,000 and bottomed around $26,000 in the mid-2010s now trades above its original price. It is not a speculator's car, though — the buyers are people who specifically wanted this shape with three pedals, many of them on their second or third M car, and they do use them. What limits the miles is the car itself: a short wheelbase, staggered tyres, and a tail that arrives without a great deal of warning mean the driving happens deliberately rather than on the commute.