When Del and Rodney leave Sothebys, the weather is clear and the street bone dry. However, a moment later when they celebrate their success, it is pouring with rain and the street is soaking wet.
While Rodney was discussing his dream with Del, he mentioned the Bible and king David's dream in which David saw 7 fat and 7 thin cows. However, this was actually Pharaoh of Egypt's dream which Joseph interpreted.
Uncle Albert mixes up the gravy and the coffee, with the guests pouring the coffee over their meals. However, when Del goes to ask if everything is alright, it's obvious the liquid being poured is gravy, as its consistency is too thin to be coffee.
Del advises Raquel's father that it wouldn't be a good idea to leave his car outside in front of Nelson Mandella house, but later leaves his new Rolls-Royce there.
Del tells James he recommends he puts his car in his garage if he is attached to his wheels. There is no way the car would have fitted in the garage with all the junk he had in it, e.g. gas cooker, etc.
There is no way they wouldn't have smelt the gravy was actually coffee before pouring it on their dinners.
Boycie deals in low quality used cars, so it would be unlikely that he would have a new Rolls-Royce in his showroom.