can anyone help with my alloys please?

7J is the width of you wheel. 16 the size, and et something in german. Theres loads of diagrams about in here which explains the et. Its basically an offset. My wheels also have an ET of 42 except they 7.5 wide. If you look on the table at the top of the forum (follow the link) It explains all, the left side of the table is the et, in your case 42. The top is the width, in your case 7, follow them both until they meet, if its green you ok if red no way, if its no way take off the thickness of a spacer if this puts you in the green your laughion. Im sure someone with alot more knowledge will point ya in right direction soon enough. Although the strange thing is my wheels have a width of 7.5 and an et of 42 even with a 10mm spacer this still puts me in the red at 32. But according to the guys advising me its fine, so how true the graph is  remains to be seen. Ill let you know as im about ready to fit them.