How do you say 愛車 in English?
My favorite car? My beloved car?

Sehen Sie eine Übersetzung

There isn't really a great equivalent in English for terms like 愛車, 愛犬, 愛娘, etc.

For example, some people might refer to their 愛犬 as their "baby". However, this sounds pretty feminine to me, which I don't feel at all when I hear 愛犬.

When some people talk about their car, or any kind of vehicle really, they might refer to it as a "she", in order to express that the vehicle means a lot to them. There's usually always one character that speaks like this in movies or games.

So, for example, if you were showing off your car to someone, and you want to express that it's your 愛車 naturally, the dialogue might go somewhat like this:
A: "Oh, is this your car? It looks pretty nice."
B: "Yeah, she's a beauty, isn't she? Just put her through the wash earlier."

Of course, it depends on how you want to express yourself in English. I don't really speak like that, as it doesn't fit with my personality, but if it works for you, then that's one way to do it.

But, yeah, overall, you establish the fact that it's your 愛車 through context in English, rather than there being a specific word for it like in Japanese.