Here at MODEL+, we generally don't recommend using lowering springs on Model 3. From our experience and feedback from the community, lowering springs will make your car constantly ride on bump stops; creating a harsher ride and worse performance.
This is due to the Model 3 factory shock being very limited in travel. When you pair this with lowering springs, it will reduce the shock's travel further.
Here is a visual of the factory shocks and bump stops:
Now imagine when the shock is compressed under load with lowering springs... not much room to work with.
We understand they’re popular because it’s a fraction of the price of coilovers. However, properly adjusted coilovers will ride and perform supreme in the long run.
If you factor in the cost of labor or time it takes to install and uninstall suspension again, it's almost not worth it to go this route. Additionally, coilovers adds the flexibility of adjusting ride height to your desire vs. springs being fixed.
If you insist on lowering springs, TireRack will have the best pricing. We also have alternative option suggestions for you. Please contact us, we're happy to assist!