cant see the point of a car cover when you are using the car daily , i only use mine on the supra , when im not using it and after ive cleaned it , mine is breatheable , think about it after two or three days grime you put the cover on and all it will do particularly if its windy will damage the paint .
on to cleaning , have a look at the duragloss range , i use these products on a daily basis , they are easy to use unlike AG , doesnt matter what temp you are using them in .
duragloss 111 is a great polish / sealant couple of coats of that will be fine , plus you can put any wax you like on top of it for a bit of bling later .
i know you said the hand wash was only a fiver , do it yourself and save all that money for some decent care care products far more rewarding in the long run .
check out janelles vee for the results of the above products , but i did machine it first