Thin perspex cut to size and bent using a hairdryer for the fog lamp covers is one way to get cheap covers.You may be able to use velcro tabs or you could just use a few small spots of clear silicon to glue them on ,personally velcro tabs cut to size would be the best .I would also consider what areas will get stone chipped and get some clear film to protect it look at tankslapper for the idea ,I am sure you do it you self if you can fins a stcokist of tghe 3M film..