An amphibious vehicle, which may plane on water, has at least one pair of front or rear wheels having wheel suspensions fitted with an anti-roll bar (46). Said bar rotates upwards as the wheels are stowed above the waterline for use of the vehicle on water. The wheels may be driven wheels, and may be steered by pivotable steering link (20); or passively steered. Anti-roll bar (46) may be mounted to the vehicle by at least one bearing (48), so that the bar rotates about a single axis when the wheels are retracted. The bar passes through watertight outside bodywork (60), where it may be sealed by an elastomeric seal (62). Said seal may comprise a lip portion (72), sealing against the bar itself or against a ring or a collar (68) attached thereto. The ring or collar may be continuously welded around the anti-roll bar.