quick question on mass production and personal modifications

There's something nice about modifying a computer in even the slightest way. I just yanked off the silly little cover to the headset jack and USB port on my ThinkPad X1. It was put there by the designers so the down-angled sides of the box would be flush, hiding the cutout for the jack and port. Now I'm happier with the machine and it's mine. Earlier I undid the keyboard and put a mSATA drive into the guts of the machine. You could argue that neither of these things would have been necessary if I'd bought the perfectly designed MacBook. True. But I wonder if setting up a computer so that it can be modified isn't a better design. I'm not suggesting such intentionality was present in the design of this laptop, but I wonder, what examples are out there of mass produced, personal products like computers and cars that are specifically designed with mods in mind? Some cars, certainly, like Jeep Wranglers. What else?