You might try something that sounds stupid, but after using it for many years it is an outstanding protectant and cleaner/detailer product.
http://www.wizardsproducts.com/store...us&mode=update
I have dark colored vehicles, I drive in all kinds of weather, since I live in Kansas and this stuff holds up really well and is not hard on the paint. I use the Shinemaster sealant on the paint after cleaning the vehicle and the Mist-N-Shine detail spray works wonders on bugs, bird crap and general dust.
I order mine from the Wizards supplier, rather than buying it over the counter. I have enough friends and others that want some of the product, I get free shipping on the boxes and save some serious cash.