さてout of nowhereとは、どのような意味なのでしょうか？
"Out of nowhere" means when something appears, or suddenly happens, when you weren't expecting. So you were really not expecting something to happen, but it suddenly occurs. And you say it came out of no where, It is a surprise to you. You can say it happened unexpectedly, or to our surprise, or without warning something happened. You can say "the cat came out of nowhere and scared us". Or "my best friend came out of nowhere while I was shopping in a mall. It was a surprise to you". You are not expecting this to happen.
Ah, yes, because instead of came out of nowhere, you can say out of the blue, also means the same thing. Yes, out of the blue. We don’t say "a blot out of the blue", but we say "out of the blue", something happened. Just "out of the blue".
Q That car just came out of the blue.
Yeah, you can say that, yes. But maybe in this case, "out of nowhere" is better.
to our surprise: 驚いたことに
without warning: 出し抜けに；急；不意；無断；突然
out of the blue: 出し抜けに.