I have a 06 Forester, which came equiped with a compact spare tire. I'm planning on towing, so the compact tire has got to go. What size/offset rim do I need? The rim is for a spare tire, so I'm not opposed to getting one cheap from a wrecking yard. Should any rim from a late model Forester or Impreza fit? Thanks.

I don't know the specific offset of your forester rims, however if you remove the rim, it will be stamped on there. Other then that, I'd just look for a rim/tire combo that is the same as your forester. Other subie rims have the same bolt pattern and are swapable.