Thats a good place to start. But how do we deem someone serious. Personal Contacts are the best since we can tell if someone is serious or not if we know them well. But these people get leads from us regardless. For example i bought a friend of mine a mini from another friend of mine this summer. Deal was made possible because of my network and confidence in both parties being genuine.
But for the newbies we would just need a platform where they can leave their numbers on a thread where you can edit the topic and make a list of sorts so that people know they're on it. Everytime you hear of a car you can send out an sms with the details to these numbers-shouldnt be too tedious as sending the same message to multiple receipients is an option in most handsets.
After you've sent out the text message, whoever replies gets more detail and then you can know how serious they are for example if they show up to meet someone you sent them to or if they go to see the car.
There might be casual fun riders but for the serious people this will be nothing short of a miracle.
What do you think?