Looking for a Hi-Vis showerproof jacket for road riding. I’ve already got a good quality waterproof so not too pricey & should pack up small – any recommendations?

If it’s just an emergency stash jacket that you want, something like this would probably be a good bet:

http://www.wiggle.co.uk/dhb-minima-s-waterproof-jacket/

Might be a bit ‘boil in the bag’ for using all the time.
I almost bought one a week or so ago, but prompted for the even cheaper one they are doing for £12 (red only though, not hi viz).