necro thread. i think the spacers i originally linked to were axle spacers designed for the rear of most cars as well as the front of the awd cars. knowing what i know now, i think you could get 25 mm control arm shim, 25 mm spacer, 50 mm wheel offset (say oem et50 to et0) to achieve a 4"/side 8" total track width increase using off the shelf components. also, some vendors sell extended lower control arms to achieve increased track width without as much shim:
https://roadsportsupply.com/3-307-xl-inner-spherical-bearing-mono-ball-end-kit-set-of-2/
the rear axle spacers just allow you to run big shims in the rear lower control arms without maxing-out the plunge on your half axle cv joints.
spacers and low offset wheels will impact your scrub radius, and aggressive lower control arm shims would impact your suspension geometry and probably necessitate adjustable thrust arms (or adjustable thrust arm bushings) and adjustable toe control arms. also camber plates to keep your camber reasonable.