Washed the Merc today. The bonnet and nearside wing look like they've been replaced at some point due to accident damage and the paintjob isn't that great. Looks like previous owners have piled on layer after layer of cheap car wax to try and shine it up a bit, leaving it kind of chalky.
I found the t-cut and set to work. A couple of hours later I have a lovely shiny all-over Merc. Result!
First time I've used t-cut for that purpose.
I also used some back-to-black. It's rubbish isn't it!