No. These hybrid forms are generally regarded as less than acceptable to English users and are not used. Several options are possible:
‚ Remove the pronoun.
Not But Someone left (his? her?) manual. Someone left a manual.
‚ Change the sentence to plurals.
Not But Everyone must drive All personnel must drive (his? her?) own car. their own cars.
‚ Use both the male and female pronouns.
Everyone must drive his or her car.Someone left his or her manual.