The BMW Z4 should be practical enough for family use if its cabin layout suits your passengers. Useful size figures include 2025 sDrive30i M Sport: 4324 mm; 2025 sDrive30i M Sport: 1864 mm; 2025 sDrive30i M Sport: 1304 mm; 2025 sDrive30i M Sport: 2470 mm; 2025 sDrive30i M Sport: 2. Wheelbase and seating matter most day to day because they influence rear-seat comfort, child-seat friendliness and how relaxed the car feels on longer trips.