New car brokers – which ones are available, which ones are recommended?

New car intermediaries – which ones are there, which ones are recommended? In the I-Net there are quite a lot of intermediaries who promise to offer a (German) new car at quite reasonable conditions. I would like to have an overview, and perhaps the information, who is serious about it, or even less serious about it. 3 come to mind:www.neuwagenschnaeppchen.dehttp://www.pkw-reib.de/www.juetten-koolen.de So far without evaluation. And how does this actually look like with problems I can imagine that they already make a difference between customers who bought from them and those who supplied themselves more cheaply on the net. I would like to know if the car is in front of the door? Talk about technical defects etc. which should not actually be and which can be repaired by the dealer on the spot.