First mod, this van didn't come with a passenger side window which makes reversing out of parking spaces and driveways dicey.
Nothing like cutting a massive hole in a brand new car to break in the modding bug. I used a drill powered nibbler as it's safer than an angle grinder (no chance of slipping and ruining the paint). Once done I tidied up the edges with a file and applied a coat of cold galv paint to the raw metal. If you let the pros do it they won't bother with this step. My T5 had a pro fitted window before I bought it and the edges are pretty nasty on the inside.
I let the pros bond the glass in. In hindsight I probably should have done it myself, but it's potentially a bit of a mess if it goes wrong.
It's still an eco mod when compared to the potential panel repairs!
Also visible are the roof racks, with such a small van, the roof space gets used quite often. Not it's still an eco mod if it means I can use a smaller vehicle.