It's new to me, but there's a meme about every lesbian wanting a jeep, so maybe this is just metonymy for, "I'm a lesbian"?

I'll need a translation for all the non normie terms of this, please and thank you.

Best that I've seen, it seems obscure on Urban Dictionary too, though note the down votes on the post:

https://pawb.social/comment/16239373

First time I’ve heard someone say it but I speak 4chan vernacular so: “a jeep” -> AGP, “autogynophile”, an ironic way of describing (and delegitimizing) trans lesbians dating back to some shitbag psychiatrist who described trans people as self-fetishists

IDK whether that's true or not, but sounds plausible.