One reason is that people who lease their cars get the cars through the leasing company. Most leasing companies are based in BKK, and therefore register the cars there.

Ford offered us the choice of CM or BKK plates. I think the BKK plates had a 5k premium. Presumably its because people don't want to show they're from the worst driving standard province.

Sent from my Cray II supercomputer

Not quite correct.  Bought my vehicle 4 years ago in Loei Province and it was registered, by the dealer, in Bangkok and has been every year since.  Was told that by affixing BKK plates and dependent on the type of vehicle, most coppers tend to wave you through at the checkpoints as they do not know the status of the person driving.
 
Don't know whether or not if this is true or not but in those four years, have only been stopped twice, asked for my license only once and I'm an expat, no one special.  in addition, given the darkness of the window tint, no one can see in, not until the window is wound down so who really knows.

They changed the law some months ago. A friend wanted a BKK plate, but it was refused.

14 hours ago, Si Thea01 said:

Not quite correct.  Bought my vehicle 4 years ago in Loei Province and it was registered, by the dealer, in Bangkok and has been every year since.  Was told that by affixing BKK plates and dependent on the type of vehicle, most coppers tend to wave you through at the checkpoints as they do not know the status of the person driving.

 

Don't know whether or not if this is true or not but in those four years, have only been stopped twice, asked for my license only once and I'm an expat, no one special.  in addition, given the darkness of the window tint, no one can see in, not until the window is wound down so who really knows.

Several checkpoints in the Chiang Rai area will tell you to wind your window down so they can see in. I do it automatically now, they just take one look and wave me through.

Its cheaper to buy a car in BKK, despite selling rates fixed by car company. With many, many more dealers there, they will give you an u official discount which comes from their sales commission.

How much better a deal are we speaking about?
Is it additional cash discount or just the crap freebies no one wants?

Yes, the people  do want the freebies, so they can sit around with their friends, and tell how good of a deal they negotiated! 

3 hours ago, bazza73 said:

Several checkpoints in the Chiang Rai area will tell you to wind your window down so they can see in. I do it automatically now, they just take one look and wave me through.

Appears they are stricter there than in the areas that I travel, north east and down to BKK and nearby  provinces.  The ones I go through just check the road tax sticker then wave me through. One time I remember a stop in Udon Thani where the BIB approached the driver's window, so I wound it down, he exclaimed that I was a farang, received a salute and sawasdee then waved me on without checking anything.