FIRST:
Just do what I did: FORGET IT. The airbag injures a lot of people and saves only one person out of 250,000 crashes anyway.

YOu can take a used one form another car PROVIDED it matches your year (due to the changes made that post 15 addressed, the 07-08s used a different module, keep reading) and, using a STAR computer or similar, reset the used module to your car. You can not order new ones for Crossfires or MB products, this is not a "Crossfire" failing, it's because the platform is not supported very well even by MB.

The 001 820 08 26[08] is used in a TON of MB products, but you can't get them anymore.



SECOND:
The only repair facility I of is these people and they dont do/no longer do Airbag modules:
http://www.sosdiagnostics.com/

THIRD:
Detailed answer from Clint, retired Chrysler engineer for safety systems (and proud Crossfire owner, he comes to Woodward, the Dragon, etc.) on the Crossfire and other Chrysler products in the 1990s and 2000s:

The airbag module had to be different for 2007-8 because the knee airbag was added. At minimum that would have required software updates, which would have (should have) been indicated by part number differences, too. But the whole Crossfire part number strategy and control was complicated by the Chrysler & Karmann & Mercedes mix of parts and control.

In some (normal) Chrysler modules the module part number could sometimes stay the same, but firmware could differ according to vehicle equipment or trim level. Sometimes this firmware could be changed or updated by dealership equipment. The bastard status of Crossfire DRB III dealership diagnostic makes me expect this is NOT possible for a Crossfire.

TL;DR short answer: No, airbag module must be different. Oh, and the idea that the module would ever have been the same as in R170 would not be true. Even if the connected airbag hardware was the same, crash calibrations would have to be different for the different cars.