I've managed to solve this for those mac users out there. Didn't need to use a PC either. Just the mac.
I had tried many expander tools to decompress the file, and they all had the street names missing. But I got it to work using 2 new things i tried at the same time, one of which might have done it or it might need both
The first thing was to use a new decompression software I hadn't used before for the .7z file. It was called '7zX (Mac)' and here is the link:
http://7zx.en.softonic.com/mac
The other thing I tried was to run the decompression of a PC formatted usb stick. I took a 16GB USB stick and formatted it using Disk Utility (standard on a mac). The format I used was exFAT. (FAT32 does not support files bigger than 4GB, which this is). I then copied the 7z file onto the USB stick and then used the 7zX software to expand it onto the USB stick. Just in case it's when the file sits on a mac volume that corrupts it.then once that is finished, I copied the files directly from the USB stick onto the SD card that goes in the car.
It may be that just using the 7zX software does the trick, so I would give that a go first and if it is still missing the addresses then try with an exFAT USB stick
You're welcome.