My attempts at buying a 2nd hand car have been...

Whilst I had a car on Friday and Saturday, I drove over to Belgium where a second-hand car dealer had a Nissan Juke that I quite liked the look of; amongst other things, it was white and I like white cars! When I started it up, there was a distinct shuddering wobble from the engine. Thinking that this might be simply due to the fact that it hadn't been started lately, I turned it off and started it again - same wobble! Just to be absolutely sure I did it a third time exactly the same wobble. This made me suspect the engine mountings were worn out; a suspicion largely confirmed by the enormous amount of engine noise that was apparent when I drove it (amongst their other duties, the engine mountings make a major contribution to damping the noise of the engine itself).
That rather put me off the Nissan Juke but, on the way, back home I noticed another dealer on an industrial estate that runs parallel to the main road back towards Luxembourg. I stopped there and had a look round, but the weather was so appalling; it was blowing a gale, pissing down with rain and most of the cars were outside so I made a mental note to come back the next day in the hope that the weather would not be quite so inclement.
Returning the next day, I found a couple of cars that I was interested in so I went into the showroom found the salesman and asked him if he could show me these two cars. One was a Nissan and the other a Seat; they were both sort of VW Golf sized vehicles. Salesman hunted down the keys to the two cars I wanted to see and accompanied me to the parking lot out front. I pointed out to him the Nissan had a smashed front valance and fog light to which he responded “oh that's nothing; it’s just a bit of plastic”. When I mentioned that bit of plastic or not it made the car undrivable, he mumbled something that I didn't quite catch so I said to him OK let's forget the Nissan for the moment I'd like to drive the Seat, to which he replied “ah, we don't do test drives, you see all these cars are unregistered so they cannot be taken onto the public roads without trade plates and we don't have any trade plates” to which I replied “what????”, and he repeated what he had just said. I thought maybe I had misunderstood what he said the first time but there was no doubt whatever what he said the second time. There is absolutely no way in a million years that I would ever buy a second-hand car without having driven it so I simply turned on my heel, walked back to my car, got in and drove off without saying another word to the salesman.

Has anyone else had this sort of experience with a garage in Belgium or Luxembourg?