I believe my husbands spying on me

I have this strong gut feeling that somehow my husband can see and hear me at all times. Especially whenever I’m in the car. Whenever we have a minor argument, he brings things I said where he was not present. When I ask how he knows that or when have I told him that, he just mums up. Like legit keeps silent or he’ll just divert the convo. I’ve searched everywhere but couldn’t find anything. Other than getting a detector, what else can I do to find this shit if there’s one?!
Appreciate it.