agreed, depending on how wet and cold the temperature is, it just packs up inside that space and rubs up against the tires. TBH though, that's going to happen regardless if there's mud flaps or not.
Is it me or do most mud-flaps get resourced from the same place? It doesn't matter if it's a BMW, honda or Mazda, they all look very similar in fit and finish.
They do look a bit different to me but could be all done by the same manufacturer.