I got my 3 last April and have always felt the ride was a bit rough. I lowered my tire pressure to 39 but still thought it a bit rough. It isn't so rough that it is uncomfortable or that it makes me dislike the car, but I never felt like I could describe it as a comfortable ride to others.
Yesterday my friend brought his 3 over to my house. He got his about a month after I got mine. We went for a ride in his car and I immediately realized his car rides smoother than mine. We then jumped in my car and after drivingon the exact same route he agreed that it was a very noticeable difference. His tires, by the way, were inflated to 42.
Not sure what is going on, but I'm going to talk to Tesla service about it. I recall that the very early deliveries had stiffer shocks or springs and that Tesla gradually went with different shocks or springs. I always believed that my car would have been one of the "softer" riding ones but it sure isn't.
My experience sounds the same as yours. I'm unhappy about the Model 3 suspension in my car, VIN is 53xxx built in July, stock aero wheels. My suspension is kinda bumpy and not as good as other RWD Model3 that I rented (that one had 19 inch wheels). My new pilot sport 4S tires are larger size 245/45 and bigger sidewall but it's not really more comfortable on bumps. It's not terrible and my friends don't notice it much because their cars don't have good suspension either, but I'm coming from a super smooth Lexus GS so I'm bothered by my Model 3 suspension. My strategy is:
1) Always ride with front tires at 40 PSI and rear at 41 PSI
2) I got new larger pilot sport 4s tires with bigger sidewall installed recently.
3) After driving 500 miles on the new bigger tires I will make a Tesla Service Center appointment.
4) Hopefully they can modify or adjust the dampers or springs to improve suspension comfort.
5) If I'm still unhappy after Tesla service center, then I move to aftermarket suspension to improve comfort, which might involve lowering a bit so springs have more travel. Problem is that I won't buy any aftermarket suspension unless I drive it first on another Model 3 that has it installed already. That's probably not possible so I could be stuck.
Related to my original post in this thread, the new tires were installed at Costco and fit properly, but I've only driven 150 miles since then. After I hit 500 miles I'll take a drive out to twisty mountain roads and start accelerating hard out of turns to check how sticky these Pilot Sport 4S are.
Summary: I always look forward to driving the Model 3 due to the comfortable seats, great screen, amazing sound system, speed, handling, and autopilot. But I'm annoyed on bumpy roads (I live in the city) and I stop short of recommending this car to others because of the bumpy ride on many roads. When I'm in suburbs or cities with nice roads (like Phoenix) I don't have the problem and the car is perfect.