So I just installed a set of Truhart Streetplus Coilovers into my 2007 g35 sedan. When I drove it with only the front coils on it worked fine, but after putting the back ones on it is extremely bouncy (To the point where going 30mph on a pretty flat road with just your typical cracks is getting you airtime out of your seat). I think it might be due to the coils having a shock and spring as one piece, with the g35 coming from factory with a separated shock and spring. This essentially made it to where I have 2 springs on the back of the car. Any tips to lessen this bouncing such as removing the seperate stock spring.
​​​​​

 

Did you leave the rear OEM spring installed? The OEM spring needs to be removed when you install coils.

 

Yes I left them in am I able to just remove them? or do a need a kit or different shorter spring to go in place.

 

OEM springs should be removed.
Check out this thread: https://www.myg37.com/forums/g37-cou...coilovers.html