Bug and tar is good option, lighter fluid is also good for junk stuck to the paint. Lighter fluid is not as strong to paint as gas would be, I consider lighter fluid to be safer than gas. This is chemical reaction, so small soft cloth sit on top of the rubber for 30 sec and removal rub, then soak again. Rubber is made of oil, tar made of oil, so using a solvent is good to get this off.
Brasso.... this idea not sure of. This is a brass and metal polish. Made for removing oxide from metal and leaves a small amount of protective finnish on the bare metal to slow oxidation a bit. Never read about this for paint or car use. I have 5 containers of Brasso on hand.... get from the county recylcer. I would not even try this.
Once rubber is gone, a paint cleaner is what I would do.... on that spot.
Then clean the whole roof so it all matches.
Polish Compound. . .. is the less agressive one
Rubbing Compound is a bit more agressive.
After rubber is gone, you cleaned the paint, see how it looks.
Any scratches, swirls, (hope the clean coat is still whole)
Then ck youtube for instruction on how to use the polish compound..... can be done by hand
once done.... then wax your car for the summer season.