Phew, it's a tough target! So low, right above the setting sun - no chance of a really dark sky before it sets. This is about the best I could do, just using Canon 400D on tripod (mind you, focus could be better but I was in panic mode!

). Various exposures, 6-25sec at F/3.5, ISO 1600, stacked in Deep Sky Stacker and levels stretched in Photoshop. 21 shots in all.
You can see the comet head quite clearly in 12x50 binoculars (easier than M4 in the twilight), but I couldn't see the tail. Faint trace of it in photo. Text & blank versions attached.
Also a stack of 11 20-25 sec exposures, really mangled in PS to bring up more detail - not a pretty shot at all I'm afraid
Cheers -