when you sell a car it doesnt matter how much time or effort or money you have spent on it or how much you are attached to the car, its all irrelevant when you're selling.
if you have spent anywhere up to $20-25k on your car in modifications, you might be lucky to get an extra $500-1000 (more than likely less) above market value for a car of that condition.. but it comes down to what people want to buy.. you could have the nicest shiniest pintara in the world, but it might not be the colour anyone wants to buy, so you luck out.
also considering the current state of the financial market with everyone in a panic, people arent going to pay over inflated prices for cars anymore which is good for buyers but shit for sellers, but the reality of it is though that sellers have been getting away with robbery for the last few years and you missed the robbery boat.