To elaborate your point - dealer margin on a DTD will be virtually nothing. 4% at best. Depends on how you play it. For high cost vehicles dealer margin is around 12%. Depending on time of year etc DTD can be between 8 and 10%, so between 2 and 4% is what the dealer gets.
People seem to have a number between 15 and 20% in their heads but it's not 1980 anymore and dealer renumeration more complex and tightly linked to sales volumes.
The higher % numbers are for Nissan Micras, the lower numbers for GTRS. Or Calis.
DTD and Breeze make their money from volume bonus, not from margin profit. In the end the dealer profits will end up being the same ish between and margin and bonus dealer, but once you start the bonus game it's hard to escape.
Top put it in numbers, EC and Breeze likely make between 2 and 3K on a Cali. But if they hit volume bonus this can be 100K +. For EC they also need to take the DTD payment out of this.
Brum make whatever margin they manage to haggle out of you - if they manage to keep 8 to 10% then they make between 6 and 8K. They will still get a volume bonus but it will be substantially less than EC and Breeze. No-one is making 15K on a Cali.