Are you trying to stir the pot?

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Two comments:
BMW, and other high end car manufactureres, do create some incredible cars but there are always things that can be improved upon. BMW doesn't always roll out the perfect product. That is quite an understatement. An example of this is how European manufacturers have to meet US regulations for bumper height so they simply jack up the car with taller springs at the expense of both looks and performance. There are always ways a car can be made better than stock. Rememner that manufacturers including BMW make products that have to appeal to the mass market and meet regulations. Some design decisions are made purely to appease the masses or to reduce production costs, not because it makes the product better.
Many mods are done because we like doing them. They are totally subjective and done because we enjoy them and want to make our rides a little more personalized. I don't think any of us would claim that any of our mods make the X5 extraordinarily better but they can make it more enjoyable and in some cases, like brake pads, camber plates, tires, shocks, springs, etc can help performance. We're not trying to reinvent the X5. We're just fine tuning it.