i sold my old golf GTI for 3k to webuyanycar.com.it had over 100,000 miles on the clock,11 years old and the underside of the car was badly corroded...(my local mechanic said he thinks it could have been in a flood before i bought it),the engine management light kept coming on,there was a strange whining noise coming from the engine etc,etc....
guess what?they DIDNT even look at the engine compartment OR ask me to turn the engine on!they had a quick look at the bodywork,pointed out a few scratches/dents and then we went into the office..
i probably could have got 3.5k for it if id advertised it...maybe.....but i just wanted to get rid at my convenience.....and thats why these companies thrive....we dont want the hassle of advertising,timewasters and tyre kickers so we take them to these guys despite getting a few quid less than their worth.....