When I was a kid back in the 60's muscle car days I couldn't wait to take the "car of the month", (they were so easy to buy and sell then, and so cheap....I had so many cars between the ages of 17-25 I can't count them all!), and add bigger tires (When 60 series tires came out to replace what we THOUGHT was "big", 70 series, we thought we had died and gone to heaven....look at how small those look now!) and a new set of "cragers" or "moonies" on chrome rims. Remember how we had to "jack the car up" so the tires would clear?
Then there was the mandatory "thrush" mufflers and headers......anybody remember that stuff??
Now....a "mod" to my cage is, as someone said, an extra cup-holder, or in extreme circumstances, that thing we put on top of the Hummer in the summer for extra storage when we travel.