After working on the Lotus Elise the airbag light stayed on. A thread on lotustalk.com told me that the airbags in the Elise are the same as the ones used in the Opel Speedster/Vauxhall VX220 and that the diagnose interface also works on the Elise. So I purchased a Opcom interface (OP-Com V1.45) on dealextreme for €20,- . It did the job. Cleared the fault codes and noticed that it is possible to disable the airbags and seatbelt tensioners. This might be handy if you want to carry a child in passenger seat or visit the track.

Op-Com interface

Lotus airbag opcom

Airbag measurement blocks