It is not hard to find the cruising areas in Manchester. I don't think this is the right place to tell you where they are. However you can subscribe to the
CRUISING & COTTAGING GUIDE
which provides up to date information about where, when (and sometimes why not) for the whole of the UK.  Write asking to be put on the mailing list.

Greater Manchester Police have stated that policing the cruising areas in town is not a priority - it only becomes so when people complain about our "activities".

Please. If you see or experience any homophobic or aggressive activities in the cruising areas, report them to the police.
"Action Against Hate Crime" is an initiative by the local Force to improve policing in the area - i.e. to stamp out these incidents. Even if you report anonymously you assist in bringing the bigots to heal. Have confidence to do this because if you do not report it, the unique atmosphere of the Village will soon be eroded as more and more of these incidents take place simply because no one bothers to report them.
Don't become a soft target.