I'd like to solder several stranded wires of a cable (maximum 18 VDC) to a PCB. I've got corresponding THT holes (⌀ 0.8 mm; it's the eight holes underneath the yellow wire,) but the wire is thicker (⌀ 1.1 mm.) What makes my issue more complicated is that the board is to be part of an automotive electronics solution which must withstand slight shocks. See the picture below:

What is a good method to solder these wires durably to the PCB?