Locking doors with one door open

We are trying to figure out when we're loading our child in the back seat how we can lock the remaining doors. When using the fob, we get a continuous buzz, and the doors don't lock. The manual says the buzz can be turned off, but it's unclear whether that setting would enable locking.

This is a habit my wife got into with her previous car, a Ford Focus. She would unlock all the doors with the fob, open a rear passenger door, lock all doors with the fob, put our daughter in her car seat, then walk around the car loading other things the same way.

With the Prius, it seems to her that while she's in the back messing with car seat straps anyone could (a) open the other unlocked doors or rear hatch and grab stuff or (b) open the unlocked drivers door, start the car and drive off with a half-strapped baby, a distressed parent, and a functioning key fob.

There has to be a workaround to this -- any ideas? Going to each door and manually locking them isn't an option with a squirmy baby.

 

OP here, I left out the detail that the child carrier is in the middle of the back seat, so when we're strapping her in, we've got maybe one leg out the door. The fob is definately inside the car during this (either in her purse on the floor, or in my pocket).

If driving is impossible with a door open, that's great, but still we'd like to know how to prevent anyone from opening the other doors and grabbing stuff.

Disabling the smart key alltogether wouldn't work, because there'd be no way to open the back door first at all.

Does anyone know if there's a way to lock the doors with one door open?

 

Yeah, I know. I'm not saying it's likely. But someone grabbing a GPS or a shopping bag from the front seat while the driver is occupied and distracted in back is a lot more likely. I'd say that sort of thing can and does happen in any shopping mall or grocery store parking lot in the US. It's never happened to us, but then again we've always locked the doors.

If thieves know that when they see a Prius (as opposed to most other cars) with a door open, that all the other doors are unlocked, they might seek them out as easier targets.

Does anyone know if there's a way to lock the doors?

 

Thanks! That's a much better solution than moving to a part of the country that's allegedly free of petty theft (besides, I'd miss the great restaurants, free museums, and employment opportunities here).

Still, that workaround means a lot of shuttling back and forth between doors (open rear door, walk around the car carrying a squirmy baby, open front door, hit lock button, close front door, then back to the rear door).

If nobody here knows, I'll try the dealer service department (would have done that first, but my wife just mentioned it to me last night). I called Toyota Customer Experience, and they said it might be possible to change at the dealer. I'll post my results.