It appears that it takes about 2 months to get your carpool sticker.
So plan ahead if your current stickered car is due within the next 3 months and you don’t want to get stuck in the even slower lanes.
1/8/2019 - Mailed out REG1000 to DMV
2/27/2019 - DMV Cashed Check
TBD - DMV mailing out sticker
Still waiting for sticker to arrive.