New exhaust has surface rust?

[UVB76]

I would say it has been sitting around for a very long time.

Yeah, that's my thought, too - it's been sitting for a while in the warehouse.

I would also expect that flange to have a complete weld around the pipe.

Good point - the 3rd pic doesn't show it but there's a full weld of the flange on the inside of the pipe. The other flanges are welded on the outside of the pipe so not sure why this one's different.

Even though it was a cheaper exhaust, things like this ^ don't give me much confidence about the overall quality.

I deal with replacement exhausts at my workshop here all the time, and what that appears to be is just where they have heated it during manufacture cooling and picking up moisture causing a bit of surface rust. That can happen in a day. Having said that, it doesn't take a second to spray these things with protector, even WD40 during manufacture. Depends on the quality of workmanship you like to portray I guess. Summare - probably ok product to use but sloppy manufacturer.

Good to know about the moisture after manufacture.
The inside of the exhaust has a residue, oily feel to it, so I suspect something has been applied - doesn't have a smell, though. It's only surface rust from what I can see so I'm not heaps worried, but it does make me question how the welds will hold up, rust around the welds, etc.