This evergreen shrub, tending towards scandent habit, has confused me enough. The yellow flowers about 4.5 cm long, remind of Apocynaceae, more so of Allamanda with opposite leaves, but four stigmas at the top of single style are confusing.
SOLVED: Allamanda like shrub from Sunnyvale
Thanks a lot TomH3787
Indeed Gelsemium sempervirens
Thanks themoonhowl for suggestion: Dendromecon has 4 free petals, only 2 sepals, numerous stamens and 2 stigmas.
Yes, I figured that one out after looking at a few pics for comparison...