I have a home built tower computer with an Nvidia GeForce GT1030 graphics card and am trying to install Neon User LTS 20171213 from a USB drive. Unfortunately, the default video driver - Nouveau - crashes on startup. I know that I need to install the nvidia-384 driver, to get my display working properly, but the nvidia-384 driver can't be added to the USB Neon User LTS 20171213 drive as it isn't persistent. Not sure where to go from here...

Same here but since the driver works for me with other installers, it's most likely from Neon's installer instead of the default driver.
The installation GUI just immediately crashes.
I'm currently running Kubuntu and I wouldn't recommend the Kubuntu -> Neon tutorials we can find here and here.
Dear devs, if it crashes with the 1030 it's very likely that it crashes with other late nvidia graphic cards.
So maybe you should fix it or just replace it with an installer that actually works.

A suggestion: change to TTY 1-6, download your Nvidia driver, install, blacklist nouveau and reboot. For more detailed info I find the Archwiki invaluable: https://wiki.archlinux.org/index.php/NVIDIA