Hello,
The current DMV refund scheme for large families requires that the family is already large when the car is bought. Given that one has more time to buy (or import) a vehicle before the birth of a third child, I would suggest (and I think the country would not lose anything by doing this) that the MTRD be amended to require the family to be large when claiming the DMV refund (which can be made within e.g. 3 months of purchase).
So you look at cars before the birth, make a decision and buy (or import) it, and then you can claim back the DMV within 3 or 6 months of purchase (or even after you have paid the DMV) (so the risk of not becoming a large family is yours). Most of us families of 4 have cars where 3 child seats on the back bench don't go, and it's a bit unkind of the state to expect us to buy a bigger car during paternity leave.
I do not think that the state really loses anything by doing this, but we would save families a lot of inconvenience. Besides, with some of the larger older cars (Sharan, Galaxy) the DMV is not negligible.
Regards,
M