...the trade in are normally bought by one of 3 local wholesalers to put on their lots or bring to auction.
...I knew that he was going to try and offload my truck to the local wholesalers.
Was it worth it? 12 hrs = $2000.... I would say so!
A successful sale involves getting the potential customer to "fall in love". Can't do that with a dealership or wholesaler on a trade in.
These are very valid observations. The trick when dealing with a "dealer" is knowing what type of cars they sell, and which ones they don't. Some new car dealers just dont' want some brands on their lots. We had a Jetta for instance that was about 18 months old and we decided to buy a new Accord. The Honda dealer just didn't want VW's on the lot. Even though the car only had 7700 miles on it, their first instinct is to "call the wholesaler, see what he'll pay". They had no intention of retailing it, even though it was a "front line" car. All that comes into play.
At the VW dealer they'd give more for it, but I didn't want a VW. (well my WIFE didn't want a VW)
Being in and around the business literally forever we both know prices and used that to our advantage.
I've got a buddy for instance that has a 2008 Tacoma. We just ran the "trade in" values on it and 'clean' versus 'average' is easily $500~$800 and there is NO BIG DIFFERENCE between the two other than appearance. Mechanically they both have to be the same, as well as mileage. It's the paint, gloss, interior lack of stains and smells, etc. that make the difference.
So yes, I would say even if you are trading in (which we all know is the worst possible way to do it) a $250 detail will most likely double that amount back (or more), IF you know your buyer. Dealers will pay less than private sales, but both will pay for the detail. Dealers KNOW that they figure a "recon" into any car that they intend to keep. Now on their lot, with their wash bay guys the average cost is more like $150 and they know that. That is not to mean however that you only get the $150 because you can argue that they don't have to do it 'in house'.
If someone pays $150 to get their car detailed before they put it on their lawn for sale, I would say It will bring at least $500-$750 more. Basically if a customer spends a couple hundred now they should make at least $500 more on the sale of the car.
Just make it clean and shiny. Only people that have a detailing hobby care about full correction.
Hopefully I addressed some of this above too.
Just to touch on the 'hobby guys' thing... I went over the weekend to show an old friend how to clean up his wifes ES350. He wanted to see it done, but nothing to do with it, NOTHING! Car is an 07, dark blue met, with over 60K on it, road trips only, not a DD. Stays in the garage most all the time. I was blown away how bad it really was! He kept telling me how it was "her baby" and how she keeps it waxed all the time. NOPE!
Made him spend about 5 hours washing, claying, and going behind me compounding, polishing, sealing, waxing. He loves the way it looks, and even understands it, (somewhat).
And what was his biggest comment??????? "If I had known it would take this much time I would have told you NO!"
Meanwhile I was doing this.....:buffing:
), bruised from a fight with a construction cone and 3/4 rims had been severely "curbed"/bad road rash (not me I swear!). Because it was in such good condition they gave me full wholesale value, $6000 more than price one tier down. 
However..... once they SEE it, they WANT it. 
