What is the test for a plaintiff to obtain relief under section 945.4 of the California Motor Vehicle Code?

[104 Cal.App.3d 32] A court does not relieve a potential plaintiff of the claim requirements of section 945.4, as a matter of course; plaintiff must first demonstrate two essentials by a preponderance of the evidence (Shaddox v. Melcher (1969) 270 Cal.App.2d 598, 601-602, 76 Cal.Rptr. 80). First, it must be shown that the section 911.4 application was presented within a reasonable time, and second, that the failure to file a timely claim was due to mistake, inadvertence, surprise or excusable neglect. (Tammen v. County of San Diego (1967) 66 Cal.2d 468, 474, 58 Cal.Rptr. 249, 426 P.2d 753.)