Maybe I wasn't too clear, I wasn't thinking of actually using a strut, just the knuckle from a strut design. The knuckle has two holes at the top that allow you to design a bolt on piece that holds the upper ball joint for use with a double wishbone arrangement. There are many ways to use slugs, shims, reversible part designs, etc to easily move the upper ball joint around within the bolt on piece. Depending on the knuckle it may be difficult to get the desired caster, KPI, etc but at least having the ability to change may be better than nothing. Sorry everyone, I think I have hijacked this thread enough.
Cobalt ball joints have 20mm shanks. Dustbuster minivan ball joints have 18mm shanks, but bolt into Fiero control arms. Yes, the Cobalt uses a larger ball joint shank than the older minivans. So maybe a Cobalt knuckle could be adapted via the use of a split sleeve around the dustbuster ball joint shank, but that's a bit klugey.