Make sure you take the car for a proper test drive—you don’t want to buy a pig in a poke, do you?
这车你一定要试开一下，可别隔山买牛。
原声例句
朗文OCLM-01单词
What if the car you buy turns out to be a pig in a poke?
【pig】如果你随便买来的车事实上并不理想，该怎么办？
英语百科
Pig in a poke
（重定向自A pig in a poke）
The idioms pig in a poke and sell a pup (or buy a pup) refer to a confidence trick originating in the Late Middle Ages, when meat was scarce, but cats and dogs were not. The idiom pig in a poke can also simply refer to someone buying a low-quality pig in a bag because he or she did not carefully check what was in the bag.