Edit to report I got this working and credit for this technique goes to somebody over at MSFN. I cant remember where I read the original post, but kudos to you if you read this
for anybody wanting to install these driverpacks from a network share, do the following:
1) Run a method 2 as you normally would on your operating system source. The folder I perform this slipstream in is called "TEST". which will be referred to as such below. create a NEW $OEM$ folder (also referred to below) with the necessary folder structures and perform the following:
2) Copy the driver packs from the TEST\OEM folder to the new $OEM$\$1
3) Copy the contents of TEST\OEM\BIN to the new $OEM$\$1\D
4) Copy the contents of TEST\$OEM$\$$ to the new $OEM$\$$
5) Copy the contents of TEST\$OEM$\$1\D to the new $OEM$\$1\D (there should now be two executables and two cleanup.cmd files located there)
6) If you selected "runonceex" as your method of install, copy: test\$OEM$\BTS_DPs_ROE.CMD & cmdlines.txt to the root of your new $OEM$ folder. (alongside $1, $$ folders)
7) Copy the I386 folder from the TEST folder to the network location where you store your i386 folders.
This is the important part. Open this i386 folder on this network share and locate the presetup.cmd file. Change the contents to:
7za.exe x -y -aoa %SYSTEMDRIVE%\DriverPack*.7z -o"%SYSTEMDRIVE%"
%SYSTEMDRIVE%\D\SetDevicePath.exe %SYSTEMDRIVE%\D
START %SYSTEMDRIVE%\D\WatchDriverSigningPolicy.exe
EXIT
Once you have this done, launch the network installation as you normally would from within BartPE or Windows PE.