My rear passenger side suspension seem lower when you look it from far behind,
and my rear right tire is showing anormal wear. Did a tire rotation this spring and now that tire is in front (this begun last summer) now my car really steer to left, i know i need 4 wheel alignement but im wondering what can cause my suspension too be that low on one side.

Is the ELC can have something to do with that or thats just a bad Shock?

I have to change at least 2 tires(after fixing that issue)

Any help will be appreciated :?

You could have a shock leaking air. Willwren posted about spraying soapy water on the connection to check for a leak. It was for the struts on the previous generation Bonneville'* but would work for yours too. I'm not sure if that would cause your wear problem, because I believe the OEM shocks are regular shocks with air assist. Perhaps both parts of the shock is bad?

Another thing to check is the shock mount inside the trunk. The shaft for the shock on my passenger side pushed right through it. I didn't notice a change in height, but it did make quite a clunking noise.

archon, ill take a look tomorow with the foamy spray, the car handle still good, no clunk noise, ill take a look at the strut mount too.

You dont think this was the cause of my tire wear?
i forgot to mention that the tire only wear in the inside, no more thread in the inside of the tire.
But the outside is still acceptable.

As we have shocks on the rear of our cars, instead of struts, I don't think they are causing that type of tire wear. Bad alignment will, but it would seem less likely for it to be that far off in the rear unless there was some parts that failed (other than shocks. ) or some type of damage. The shocks will not affect the alignment like struts do.