only thing I found was to get one car loaded up in the garage waiting while the other is arriving at its delivery destination and then start the delivery for the first so by the time it gets there the first delivery should be done or soon to be. It can eventually get backed up to same problem again but its temporary fix and possible permanent.

i had that issue before, too much production, not enough logistics to get it sold. the work around i went with was selecting all of the types get shipped in each car, so whatever you make is what gets shipped with that you can add another car if you want to keep one waiting all the time. then adding more people at the delivery point set to unload cars. i tried to keep enough that with one trip they would unload the vehicle coming in. so the car hits, four people go out and grab the stuff and store it, that car drives off and another moves into its place. want to watch out with work schedules so everyone isn't on break when the cars show up. another thing is you can have people there around the clock so you could do deliveries after hours if you wanted to catch up. if you're just wanting them to cycle cars faster at the laundromat, make shipping a job duty of everyone, they will stop selling but they will go unload immediately when a car shows up.

but ultimately the shipping is a flat cost each day, better to have them waiting to unload than sitting empty at the farm. if you're really not wanting them circling the block though, you can send one or two to the junkyard or university instead of the laundromat, to get points building up.

so... the game is a little uneven right now. basic weed sells more than the other because if a guy asks for any kind of weed in your shop front it will always say we have basic weed, want that? and the buyers always says yes. nearly all buyers want basic weed. so your margin in production should reflect that. meaning you should have a big basic weed setup and medium toasty weed setup and a small amazon setup (at least to begin with). people will ask for toasty and amazon but buy basic if you don't have toasty or amazon. so once there is only toasty and amazonian in your front buyers will start saying do you have basic, and they will buy the next available one. so you just need to fix your factory to sell to the highest demand.

Also you might want to set out an additional worker just for packaging vans, bike, cars and trucks i found i needed one worker just to get the stuff from the ready to deliver to the vehicles, its like a full time job. remember that workers need to be told where to sleep, rest, eat, relax and where to go to the toilet, if you don't set up rooms for each worker they will not work in the correct area. they wont have their needs for filled and just stand around or work in jobs they haven't been set

having 1 shop front per product type is key, also as mentioned above "get one car loaded up in the garage waiting while the other is arriving at its delivery destination".