i just bought 2003.5 m3 vert.
it hydro-planing real bad in rain
i was going 75mph which i usually do on freeway with my is-250, i feel like my m3 will spin out. it's not only feel weird in rain but also in normal condition road specially on the freeway! accelating between 50~70mph i feel a lot of vibration from rear! but when i gunning it, i don't feel that vibration some how!
another thing is when i go over lil bumpy road, it feel like rear end acting like it's on rail (feels like it want to follow trail of bumpy road)
i checked my tires, it was fine!
help plz! help!

p.s. i am sorry about my english, i'm not a native speaker

check the RTAB (Rear Trailing Arm Bushing)

If it's bad, your car axle will slide back and forth horizontally making it feel like the rear axle is loose and out of control.

the OEM RTAB is rubber and easy to wear out...search the forum for RTAB.

thank you very much! i was worry maybe it's diff
i love ya!

sounds like bump steer to me but rear trailing arm bushing sounds about right

Let's see....maybe you should slow down when it's raining.

Let's see....maybe you should slow down when it's raining.
50-70 is not that bad when its raining.

Let's see....maybe you should slow down when it's raining.

Too funny!!! hahaha

I know I had to slow down once when it was raining but I couldn't see the lines the water was so deep so I am sure that was an extraordinary situation.

What kind of tires? Not all the tires hold the road good at rain.

Let's see....maybe you should slow down when it's raining.

+1. 50-70 when your losing grip...you're just asking to hydroplane

i just bought my M3 so i was testing out how M3 react on water.
i have michelin, it comes with oem 19" i think.
one more thing that i did mention was my handle is shaking a bit, it feels like tire balance is off or something.

i just bought my M3 so i was testing out how M3 react on water.
i have michelin, it comes with oem 19" i think.


You might want to get under there and see if there is actually any tread on them.

A narrow all-season tire, like on a Lexus, is going to be better in the rain vs. a wider performance tire.

This is the exact feeling you get when you drive in the rain with bald tires (especially the rear). It gets real squirrelly and if you not careful it will come around on you in a moments notice with warning. Be careful and look at the tread depth. The feeling is very scary in an M with bald tires in the rain; even below 50.....

I'd look at the RTABs.

50-70 is not that bad when its raining.

50-70 in the rain can be quite bad if conditions don't warrant those kinds of speeds.

With 19" wheels your car will tramline (follow the joints and cracks in the road) much more than with 18" wheels, regardless of tire make or tread remaining.

Your problem sounds like worn out tires though.