https://www.youtube.com/watch?v=XtD9eci3yXE -> Startup sound + idle. Note : it seems that a little throttle is put so it's not complete idle. IMO, real idle is at 02:17 (hear the transition). + Midrange revs near 02:30.
https://www.youtube.com/watch?v=T10w7lqWw1o -> Startup at 00:10. very slight rev up at 00:17. The rest of the videos is the car driving off and racing hillclimb (fly-bys). The Idle sound car be heard again at 00:33. It's important because the following video confused me a bit.
https://www.youtube.com/watch?v=fwsYXToLixg -> The video starts with some fly-bys for 30 seconds. Then at 01:17 the car is started up. Idle has way more rumbles than others videos (I don't know why) then it is warmed up a bit with very very gentle revs.
The rest of the video is fly-bys + onboard (sounds slightly gopro-ish)
https://www.youtube.com/watch?v=oFpFDyz5fyk -> startup at 00:07. It seems that the startup / idle is a combination of rumbles + idle from first links I gave here. Some warmup revs until 00:37. The rest of the video is lovely fly-bys.
https://www.youtube.com/watch?v=MPgq5Zz0ARM -> Probably the best sounding startup sound I found (could be even used for interior and exterior at the same time) at 02:14 with INCREDIBLE sounding revs. At 02:51 it's inboard but sounds really gopro-ish.
https://www.youtube.com/watch?v=Irnr8E86EDI -> startup from the cockpit at 00:05. The sounds are usable up to 00:20 (after it gets too windy) but the quality is good. Around 02:40 sounds may be usable again (going back to pits) until 03:24.
I hope this helps. Each time I'll post a new thread it's at least a few hours of browsing and listening / comparing. I selected what I thought was the best, as always. There are more videos for this car but either more fly-bys or very bad quality inboards.