I worked on my friend's metallic silver car today that was covered in small yellow spots that were deposited by some birds when he parked under a tree for an extended period of time.
They weren't gooey or rubbery so I knew they weren't sap.
First we washed the car to get as much off as we were able.
We then used Turtle Wax rubbing compound (rust colored) very gentley and carefully, both by hand and with my Black and Decker (purchased at Sears for under $100) random orbiting buffer with a terry cloth pad. This buffer works well for the weekend detailer who might used 3-4 times a years. I've had it for at least 10 years and it still works great for my purposes.
This stuff needs to be rubbed off before it dries.
We then hand rubbed the entire car with a wet terry cloth towel and Gel-gloss to remove the remaining spots. Gel-gloss is a liquid clay bar substitute. It also lays down thin but very smooth and shiny finish. It also can remove light scratches. It's not advertised as an auto product but it's done very well for me over the past 15 years. Since it leaves a bit of a finish, I use it between detailing to remove just about everything that sticks on or scratches my car. I get it at Home Depot.
Gel-gloss will set you back about $5 a can. It also comes in a spray. I've also seen it for sale by the gallon.
The car come out great and my buddy was pleased.
We ran out of time so next on the list is to give it a couple good coats of wax.
I know most of the forum members use other products and that Turtle Wax has a poor reputation so I like to post success stories for cheap products that produce excellent results and can save lots of $$.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition