you shouldn't expect to get back what you put in

[Steve Tinker]

It really depends on the "mods" made to the car - a Raby built 3.6 engine mod has a totally different return cost to a purple leather interior....

We've seen many times on Forums pictures of some idiots idea of upgrades which (at least) cause laughter and (usually) ridicule from all.
As tonycarrion says its very personal, especially if the mods are visual (purple leather) or sensible (IMS upgrade).

Call me old fashioned, but many people who are shopping for a particular vehicle seem to always say that they are looking for a low mileage, original & unmodified car. And this is born out when it comes to trade in time - unless its a genuine factory upgrade like GT3 kit, most dealer will knock $$ off the car because difficult to remove mods = difficult to move cars.

[vijen6]

Agreed. When I spend $ on mods, either I keep the stock parts to put back on the car when it comes time to sell, or consider the $ a lost. Spent for MY OWN enjoyment of the car.

Taking off the part and reselling it as use part usually net higher prices when sold individually than as part of the car anyways. Usually.

Same with maintenance $ in my own experience. If I know I'm about to sell a car, I don't do much more maintenance. For example, if the car needs brakes, I'll 'negotiate' $1000 off the car so they can replace it themselves. Most buyers seems to prefer getting this 'deal' even if it works out to be exactly the same in the end.

[eightsandaces]

I don't care what the mod is, anyone thinking a car is a monetary investment better be buying something like a Hemi Cuda. Even then if purchased just for investment potential then I say what's the point? I always go to the IP car collection when in Vegas, after the fourth car I start thinking "what a waste and hey, where's the keys to this Alfa Romeo"?