Errrrrr dude, seriiously, you are concerned about 3-4 days and no calls? It will take you 6 months AT LEAST to sell your car - you may not have a single phone call in that time, unless you advertise it at a bargain basement price (and even then you will struggle) ..... the car market is the worst ever. It took me 8 months to sell my old R34 for $18,500 and it had $20k of mods on it .... different car, but you get the idea.
Our cars are a double edged curse ... they are awesome and seem unique cos no-one knows what they are and the average Joe thinks they are worth MUCH more than $20k-$30k (people are SHOCKED when I tell them mine is 8 years old and only worth $30kish). But, by the same token, because no-one knows what they are, people aren't out there looking for V35s. And those that are have a LOT to choose from (check around on Ebay, Carsales, car yards etc). Sad but true.