Thanks, didn't fancy the experiment if it went wrong!If they are standard Rover alloys (original spec) you will be fine.
Ok, I'm off outside to give it bashYeah, it's fine to spray on while the wheels are on the car, but you will find it easier to clean if you take them off. Don't worry about a little overspray, just rinse it off.
You might want to follow it up with a sealant to keep them really shiny. Something like Poorboys Wheel Sealant is excellent.