Do mods lower value?

[HikerToo_imp]

I was wondering if everyone out there modifying their CB1100 thinks this will help or hurt their resale value when they go to sell or trade it in?
I know with cars, I would prefer one that is well kept and 100% stock...I don't want one where some kid has been adding wheels, brakes, nitrous, blacked out windows, etc. In my mind that cheapens the vehicle and takes away from selling price.

I also know that most people doing mods, at least in their mind, think it adds to the value because the next person does not have to do them.
As of now, mods I have made are a small wind shield, and will probably add a Staintune slip-on soon...

So, does it add or subtract?