[RobSC]

If you choose a later model Newell with ZF suspension parts, Newell may be your only source for these parts.  ZF is very strict with who they allow to sell their parts.  Aftermarket suppliers are very limited within the US.  Others on here have had success using sources outside the US, but shipping costs will be high.

I recently priced a replacement air spring (bag) from Newell that was in stock.  Sit down for this one, $1,139.99.