Again, not exactly a question. More like beat poetry, but I'll take a stab, Jazznik. You are wondering if his car runs on condoms, right? No, no it doesn't.
However, from what you're telling me, he may be cheating. It is certainly reason for you to suspect he's using condoms with another person. A vasectomy protects against pregnancy, but not STDs. He knows that, the mistress or mister knows that, and so that would explain the condom.
Could this all be a misunderstanding? He keeps a condom in his glove box just to prove to his friends he has sex with you, or as part of his civic duty in the event he passes two homeless men engaging in anal and wants to keep it clean? Yes, but you need to confront him on it. He may have a non cheating answer to your question, but it's 100% worth probing. If he already did, you need to know and get in the driver's seat on this.
Funny Guy
Yikes! Unless he's moonlighting as a clown for hire at birthday parties/other events and is making balloon animals out of those condoms, I think you may have to start questioning his loyalty to you and whether he's being honest with you about the state of your relationship.
Have you considered that they may be old, i.e. from BEFORE the vasectomy? Condoms take years to expire.
Also, he may just keep them around out of habit. I know that even when I'm single or in a committed relationship where condoms aren't used, I still keep some around. It's better to have condoms & not need them, than to need condoms & not have them!
Don't jump to conclusions, but do ask him. If it's either of the above reasons for him keeping condoms in his car, then he won't hesitate or have to think about it too much before he tells you so.
Good god, I have condoms in my car. Best emergency water carriers you can find.
Definitely worth asking about, even if he's just using them to fill with water and chuck at passing cyclists it's worth it for the peace of mind.
just ask. my bf always had condoms in his jacket pockets, which i found weird since we don't use them (only after being in a monogamous relationship/we've both been tested for everything). he explained that when he used to go out before me, he would always put condoms in his jacket "just in case". and it's not like once we started dating, he went through every single jacket pocket to remove them. when he comes across one, he'll dispose of it.
i don't think it means he's cheating. he may be, but if this is your only evidence, i wouldn't be entirely convinced.