Personally i think most people do not understand the fundamentals of how their suspension work.
For example if they decide that they want to lower the car and ask for recommendations i want to understand the reasons why they want a new suspension or perhaps why they want to lower their car. The reason is simply because there are benefits lowering a car especially if you want to reduce roll and be quicker on track however there are also drawbacks and more specifically reduced suspension travel.
I came across an interesting talk about aftermarket suspension - not specifically aimed at a particular brand but more about the design principles that went into some brand offerings and how their adjustable coilover designs work and goes into the why some adjustable coilover designs will be compromised by using off the shelf standard damping chamber components matched with various bottom housing compared to adjustable coilovers made specifically for the mx5.
I highly recommend anyone who is interested about car suspension to watch this.
I also believe not enough is being said about the importance of swing bars and how they can influence your car handling. Again for the same reason as above i highly recommend watching this video to explain the reasons why one should look into adjustable swing bars.
Further and somewhat extensive discussion can be read here