Rust on a new EV: an awkward chapter for MG and BYD in Europe

MG ZS EV, MG4, MG5 and BYD Atto 3 owners are sharing photos of corrosion. Surface rust, the perforation warranty and what to check before buying.

Chinese electric cars have picked up an awkward talking point: owners of MG and BYD models have started posting photos showing signs of corrosion. It is not yet a mass problem, but the cases are visible enough to notice — especially against the rapid rise of Chinese brands in Europe.

With MG, the complaints mostly concern the ZS EV, the MG4 and the new MG5. Owners are showing rust on the underbody, weld seams, lower body elements and individual structural parts. Most reports come from the UK and Germany, where damp weather and winter road salt put any anti-corrosion treatment under serious pressure.

The contentious point is the warranty. MG advertises a seven-year corrosion warranty, but it mainly covers perforation of the body — rust eating through from the inside out. A film of surface rust can fall into a grey area, and that is exactly what frustrates owners: the car is brand new, and the argument with the dealer already feels like a forensic case.

BYD has also drawn criticism. Notable cases involving the Atto 3 have surfaced in Australia and New Zealand, where roads are not salted. In one episode, part of the car had to be repainted, and BYD covered the repair, said to cost several thousand euros. Possible causes mentioned include poor metal preparation before painting on early batches, stone chips and a coastal climate.

BYD says its cars meet strict international corrosion standards and that it uses electro-galvanising with a thin layer of zinc. In the cases reported, the brand has carried out warranty repairs and brought in local teams to inspect.

The takeaway for buyers is simple: a Chinese EV needs to be checked for more than just the battery and the software. The underbody, wheel arches, weld seams, fasteners, door edges and any stone-chip marks are now mandatory inspection points too. Price, range and equipment matter, but on the used market rust eats into both the saving and the residual value very quickly.