For what it's worth, I found this list on CHRYSLER CROSSFIRE ROADSTER/SRT-6 04+ ICHIBA WHEEL SPACERS VERSION I 10MM
for hub-centric spacers.
This would SEEM to imply that any of the wheels from any of the MB models will fit the Crossfire hubs, you are on your own as to brake clearance and wheel bolt length :
( they have spacers from 5mm - 20mm )

Fitment:
Audi A4 09+
Audi A5 08+
Audi S5 08+
Mercedes-Benz R171 Slk280 Slk350 Slk55 Amg 04+ Fr &Amp; Rr
Mercedes-Benz W203 C230 C240 C32 Amg C320 C55 Amg 01+ Fr &Amp; Rr
Mercedes-Benz W209 Clk320 Clk350 Clk500 Clk550 Clk55 Amg 03+ Fr &Amp; Rr
Mercedes-Benz R129 300Sl 500Sl 90-96
Mercedes-Benz R170 Slk 97-03
Mercedes-Benz W202 C220 C230 C280 C36 C43 Amg 94-00
Mercedes-Benz W208 Clk320 Clk430 Clk36 Clk43 Clk55 Amg 97-06
Mercedes-Benz W210 E300D E320 E420 E430 E55 Amg 96-02
Mercedes-Benz W163 M-Class 98-05
Mercedes-Benz W164 Ml350 Ml500 06+
Mercedes-Benz W221 S320 S350 S450 S600 S63 Amg 06+
Mercedes-Benz W251 R350 R500 06+
Mercedes-Benz W140 S320 S400 S420 S500 S600 92-99
Mercedes-Benz W204 C300 C350 C63 Amg 08+
Mercedes-Benz W220 S320 S400 S420 S500 S600 00-05
Mercedes-Benz R107 350Sl 380Sl 450Sl 560Sl 71-89
Mercedes-Benz W123 300-Series 76-85
Mercedes-Benz W124 300E 400E E320 E420 87-95
Mercedes-Benz R230 Sl500 Sl550 Sl600 Sl55 Sl65 Amg 03+
Mercedes-Benz W211 E320 E350 03+
Mercedes-Benz W219 Cls 04+
Chrysler Crossfire Roadster/Srt-6 04+