Baja Mexico shrub

Turraea obtusifolia (Star Bush, South African Honeysuckle) is what the flowers and the leaves look like, however they also look like Star Jasmine, but as for the fruit, I can't help there. The fruit of the SA Honeysuckle is a segmented green capsule, 6 x 13 mm, like a miniature pumpkin, splitting and peeling back to reveal shiny orange-red, kidney-shaped seeds (Feb.–June). All parts of this plant are poisonous.
Can I suggest that you cut off a branch when it is in flower and fruit and take it to a local plant/garden centre, I've searched all of my sources and cannot find anything which totally fits your description - best of luck finding it.

I think I have found it - Carissa macrocarpa or The Natal Plum and the fruits are edible, but please check this out and make sure I'm right before you eat it and end up poorly!!

This is the web page where I found it
http://images.google.co.uk/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/6/67/Carissa_macrocarpa.jpg&imgrefurl=http://commons.wikimedia.org/wiki/File:Carissa_macrocarpa.jpg&usg=__nCVIINheWbGHKQkEyDM0ApNIzeU=&h=1200&w=1600&sz=418&hl=en&start=2&tbnid=WNOV2oP_sHb_gM:&tbnh=113&tbnw=150&prev=/images%3Fq%3DCarissa%2Bmacrocarpa%26hl%3Den%26sa%3DG

You're welcome, no problem