If they're being dumped there is an oversupply, and people are spoilt for choice. The market is awash with the dumped product.
Not being able to buy them is the exact reverse of that.
Your claim is that the reason people cannot buy the vehicles ISN'T because they are being dumped BUT because the government SAYS they are being dumped and has therefore actively prevented them from being sold.
The supposition is that it's an accurate claim by the governments - there are reports that the Chinese manufacturers are being restricted by their government and that there has been a period of over production, but how much of that is true and how much is propaganda is very difficult to actually ascertain.