A little positive reinforcement, a treat kept in a bag that makes noise when opened, when strangers come a calling can help with that fear.
Mine just goes off to another room on her own, not caring for strangers herself.
One time she mistakenly thought the company must be gone, for she poked her head around a door jamb to see if the coast was clear. Nope. She literally rolled her eyes and swung her head to the side - just as humans will do when the idea is, “Oh, fer f#%ksake,” and went back off to hide. 
Goodlooking cat, there.
That sounds like a brilliant idea which I shall implement forthwith! 
The last person he opened up to cut off his nuts. It SHOULD be a while before he trusts another human.
Our vet offers neutering or a vasectomy.
Whichever you choose, be careful. You don’t want to end up with a high-pitched voice.
I’m hoping for a job opening with the brothers Gibb.
Just a thought, speaking as a vasectomised male meself - a mere vasectomy wouldn’t alter a tom’s behaviour apropos of spraying, wandering and, er, tom-catting… bit of an issue this sterilising business with cats but we do have an awful lot of cats around…
No I don’t go around spraying and tom-catting. You know exactly what I mean. 
The idea is not to change male cat behavior. Female cats are induced ovulators. If a vasectomized male mates with a fertile female she will likely be taken out of the breeding pool for four to six weeks. She will have a pseudo-pregnancy, otherwise she will go into estrus every 2 to 3 weeks. For those irresponsible enough to let their cats free roam or maintain TNR colonies, a male vasectomy, providing sufficient numbers are vasectomized, can have a very big impact on feral populations. An un-neutered male will hold and defend a larger territory that may contain the territories of numerous females and he keeps out other males and reduces the amount of recruitment from non-feral populations.
Yeah but what if I don’t want my accidentally-left-open car to stink of tomcat pee… 
For male cats pee is like success, your own always smells good. Why would you want to deny them?
jealousy?
So you two have never had tomcat pee aroma gracing your car upholstery, huh?
Not only that but the bugger ate part of a birthday cake a friend had baked for our eldest. The aroma wasn’t nearly as bad as the aroma from an injured Bald Eagle, who had obviously been eating many “aged” dead fish, who defecated all over the interior of my vehicle and me while I was driving pell mell to an emergency vet. That’s aroma! 
A heron rookery smells like heaven by comparison.
hell no! He knew that if he asked I’d pull over, roll down his window and wait for him to come back.
I’ve only read the title and saw something about cat pee. Did it not cross your mind that maybe it’s not just cats to whom you are a disappointment and maybe they’re just the first to communicate this to you. I always try to look at the positive.
Careful, or you’ll get what Monty got.
Or not got…
There may be some merit to this line of thinking. The roadsign to personal growth sometimes appears unexpectedly . . .