Are all the cross-boundary vans in Hong Kong illegal?

You know the type: black, with dual, sometimes triple, vehicle plates and, until recently, it was either an Alphard or a Vellfire. Yes, these are the famous cross-boundary vans that will whisk you, your family and friends and luggage between Hong Kong and the mainland or Macau…for a price you negotiate.

On my drive across the Hong Kong Zhuhai Macau Bridge today, I noticed a couple of vans matching this description pulled over by police on the access road to the vehicle departure plaza. Upon seeing this, my mind jumped to an event that happened a few weeks ago. Soon after the new Huanggang port opened, there was a night when traffic became backed up. In response to media enquiries the next day, the spokesperson made a comment reminding people not to take illegal transport and that they would confiscate any vehicles used in such cross-boundary transport. Could these two events be related?

As if the Hong Kong Government was reading my mind, this evening, much to my surprised, I received this email from the Cross-Boundary Vehicle unit of the Hong Kong Transport Department:

This got me to thinking...how can one even tell if a private vehicle is properly licensed with a hire car permit? The vans I've very occasionally taken across the border are those that appear when you book them on Didi's 粤港车 function or that you can reach out to via Xiaohongshu ads. They always seem like they're dispatched by semi-organized...bordering on professional operations. However, I've never seen any sort of sticker or paper displayed indicating that they might have a hire car permit. But are they actually all just illegal just like Uber?