An excellent finish to an enjoyable series. The second star-trail is terrific - the darker sky and the cactus silhouettes both working superbly well.
Thank you David, that was my second attempt (only one per night possible, for obvious reasons) and it worked better because I had learned from my previous mistakes.
Pity I resolved to do it late, it was shot on my last night (finished at 1AM, got up at 6 to drive to the airport).
Shooting star trails is not that difficult but one has to be very methodical and make sure of every detail, otherwise post-processing can become a nightmare (or downright impossible).