if you want to get rid of bugs from just washing the car then get a bug remover sponge, these are just like a sponge covered in a material the sme as a stringed vest sort of thing or you can get the plastic ones (but i dont like using them on my paint) as for the engine i use an all purpose cleaner and do it all by hand then cover the plastics in a plastic dressing to give it some shine andit looks like this after
the only difference now from when i took that photo is that i have chrome air con pipes now from where i have polished them up with metal polish lol
if you are after some car cleaning stuff i can sell you some good stuff CHEAP as i do it for a living and buy in bulk, so if you dont mind having your stuff in coke bottles i can sort you out