It is... problematic.
I have now had both the bigger tires and the lift for a few weeks. I have to say I love the new feel and the freedom to wander familiar roads that have been denied me before the lift. But mechanical issues and efficiency reductions are nagging me.
The first problem was an occasional clanking sound that would come and go, it was not consistent nor readily replicable, so I was reluctant to take it back to the mechanic for investigation. I thought it might be the new aluminum "smash me" underbody shield flexing too much. After coming home from one drive I crawled under (much easier now that its almost 3 inches higher above the ground) and noticed a piece of something loose sticking out a gap between the rear underbody aero shield and a suspension member. I panicked and thought the new rear camber arms had somehow broken loose? But then how could the vehicle be drivable? I tugged and shoved at the loose cylinder, which felt like it was still attached at the far end, but then I managed to extract the thing: it was a folding flashlight with a powerful magnetic base. Apparently left up in the suspension by the alignment shop. Most of the time the magnet would stick to something an the flashlight would rest peacefully. Hit a decent bump and the flashlight would rattle around in the suspension area, unable to fall to the ground because it cant fit through the gaps in the aero shield. It would rattle around until the magnet would find something to stick to again, and then the noise would stop.
I had the mechanic lift up the vehicle to inspect for any damage from the flashlight being stuck in wheelwell for 500 miles, but all looked ok.
A few days after that, I found some random hardware in the cubby of my front passenger side door. I have looked under the vehicle briefly but did not see where these might belong. There is a creaking sound that seems to be getting worse, but again not consistent. Recent work: tires, wrap, MPP lift, front smash plate, and "brake service". Any ideas where these screws and panel inserts might belong?
Clearly at this point I am loosing confidence in my mechanic and in the car. The final thing is the reduction in efficiency. Sure, I was expecting some. But based on reports from other people lifting I did not expect as much of a hit as I am seeing. Before all this my car lifetime (34k miles) consumption was in the ballpark of 280whr/mi, mostly highway. Now I can't get it under 310 even driving in town. And pushing 340 at 70MPH. Some of that is odometer error because the new wheel diameter, but it seems excessive. Given the alignment shop left a flashlight in there, I may try to get the alignment checked by a second shop. Or maybe the "brake service" is causing new brake drag.
Should I just tuck tail and go to a Tesla service center and have them check it out? I think they will refuse to even look at the vehicle because of the non-conforming non-OEM parts: underbelly plates, lift, tires.