As a general rule here in the states begin with either Lotus or Delorean websites. Google both and surf em. Parts are here in the USA for Renault's but it does take some web work however.
Then the guys in the UK have always been helpful. The GTD pages, Southern GT, and the Tornado page can help also along with Chris Cole who has helped me in the past.
Lastly this is after all a French gearbox. The guys across the channel have posted a lot of information on Renault's
All of these sources can be found here on the forum in one place or another. Search engine might help ya.