If you take your VIN and your personal ID to a Mercedes dealer, the dealer will know the proper key to fit your trunk.

This assumes, of course it hasn't been changed since the car was produced.

Since your ignition key won't work trunk, something's changed, but it's more likely the ignition switch was changed.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles