looking at larger aftermarket exhaust system for a 2.2 and 2.4 costing from $400-600, a SS exhaust would do the same job as aftermarket system and cost alot less, going from a 2" to a 2.5" dia mandrel bend system should fit without any modification.
has anyone installed a SS exhaust on a non turbo hhr

Good question...for purely selfish reasons..

If I decide to go aftermarket on my SS, who might I peddle my stock exhaust to?

It's been done. I sold my SS piping to a friend who has an '06 HHR w/ the 2.2 and a custom supercharger setup (he used to be on here). The only change needed was the flange at the header collector, everything else fits fine.

Later
Allex