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Old Mon, Nov-26-2012, 01:45:50 PM   #20
Carlos is My Co-Pilot
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Originally Posted by crqflier View Post
Fun exercise.

Did you state your r2 or r-bar? If not, what were they?

My guess is you'd have a more accurate model with some additional variables as others have said. I'd say accident history (# of accidents), rust, and some variable for maint history would all have a statistically signif impact. With that said, fewer variables is better for a given accuracy.

Next step - you need another 50-60 people to use your model and report back the results vs. actual price paid. A model that works with the data used to create the model is one thing. A model that works with new data is another. For me, primary model over-estimated by ~$1000 and mileage/year model for coupe underestimated by ~$1000.

Still, being within $1000 is pretty solid, all things considered. This model is certainly enough to see if you're in the ball park on a given price.

Originally Posted by M3WhiteSedan View Post
If you want good data you need to make a drop down selectable form linked to a database and more clear explanation of things. The OP clearly is ignoring my posts, but why is unclear.

Sent from my SCH-I535 using Tapatalk 2

Maybe he's ignoring you because you're the only person out of everyone who has seen this thread asking him to do even *more* work instead of simply re-reading the very clear instructions in the first post and figuring it out for yourself.

It's clear as day: plug in your personal variables (mileage, age), deduct for vert or coupe and it gives you an approximate value (or price if you're using this as a buying / selling tool). It's not rocket surgery. There are other variations, but that's the basic formula. Takes about 45 seconds with a calculator and that's if you have a hard time with long numbers.

75 years and 350,000 miles of fun:

1998 M3/4/5 No mods, just maintenance

1983 CJ-7 No maintenance, just mods

1983 R65LS No intention of modding it, don't know how to maintain it

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