oh and obviousley you dont do it in the sun you probley know that,but my neighbour obviousley does not anyway its a laugh watching him do it
Polishing cars in the sun is a urban myth, if you use a cheaper polish like kitten,repo etc etc, it will be harder to buff of in the sun, if you use superior polish like AUTOGLYM SUPER RESIN POLISH (retails for around $60 for a ltr) it will not dry in the sun and can be buffed off really easily, also you can leave it on the car for up to 24 hrs and it will still buff off as easily as it would as if it was only on there for 10mins.
TRXBOI, you shouldn't have any problem with your polish, so long as it is not kitten no 2, kitten no 1 should be fine, maybe before you polish use a paint cleaner to remove anything that might react with the polish ( this is unlikely, in two yrs of selling trade qaulity polish to automotive detailers I have never heard of it happening), then polish your car and then use a wax to protect your car. Most people I know don't wax their car, it is no good just polishing your car, all that does is make it smooth and shiny,wax will protect the paint when it rains as polish washes off after a wash or two and it puts a harder coating on the paint to protect from stonechips, also you only polish a car every 6 weeks generally ( I polish my car every 4), so every fortnight apply wax i,e: polish, 2 weeks later wax, 2 weeks later wax then in another 2 weeks polish and repeat the process for as long as you wish, this will keep your car looking better for longer.