Back in a Z again.
 

Hi, depending on the coilovers, you may have an adjustment screw on them, for softer or stiffer ride. Depending on how low the car is, you may also have no suspension travel, aka, jarring ride quality.

For headlights, this guide is really good:
http://www.hypersprite.com/auto/tech-z-003/index.asp
You will need an 8 inch #2 Phillip's screw driver.

As for the seat, I suggest looking at the mechanisms and try to figure out if there is an issue.

Make sure to search if you have any specific questions, theres a good chance the answers are already posted.

The car looks good, has definitely been modified a bit, but clean looking. The top hat of the coilover (in your engine bay pic), looks like there is an adjustment knob there. It could be set too soft causing the bouncy ride, or perhaps your shocks are blown. I don't have experience with those coilovers, but from my research, they should be a stiff ride, but not bouncy as you explained.

Hard to tell from the pictures, but the rear looks like you have a spring with an adjustable seat in your spring bucket. You can raise or lower the car by adjusting the spring seat. I would suggest taking the wheels off and giving all the suspension components a thorough inspection, if you're unsure of how it was installed. Also I usually search with google this way: "(what you want to look for) site:my350z.com"

I've had a good amount of experience with coilovers and they should not be bouncy. There are a few things it could be, the first I would check since it's the easiest is what a previous person said, check the dampening if they have it. By the looks of the pic they might not. The second thing would be to check the springs pre-load, for this you would have to take them off the car. The last thing is like the others have said, could be a blown coil. I would be willing to bet that it's most likely the pre-load since hardly any novice DIY mechanic knows to set that up correctly. If you need a walk through message me!

thank you fiddy_sent! I did pull them apart yesterday and found a few things incorrect. Tein sent me the flex install manual and I just reset them up. The front was set to 0 for the damper and the rear was on 4 or 5. I adjusted the coil to the recommended starting point, 1.0 inch. The rear the shock was never turned down from factory height, so I set it to the recommended setting and the coil spring was upside down with no adjusters... I flipped it around and put the adjusters back on (they were in a bag luckily). I did raise the car as well which is what I was after since my driveway was killing the car, now its OK, I may even be able to drop it down a bit more (spring time fun). I had to order some spanner wrenches so I could torque the settings (Tein Spanner has a hole for he torque wrench) once I have them tight I will have the alignment checked and corrected as needed. I had to drill out the small hole on the rear strut tower so I could get a wrench down to the damper... I am looking for a nice cap to use for the hole... but my starting point (per the manual) will be 8 on the damper... so I will see I guess... Thinking with the front so low (it was like an inch from the ground) and set to 0 on the damper its what was making it so ruff... ill know more after I get it tight... I dont want to drive it till I am able to torque it up... I only have the one spanner and I used a screw driver to tighten it some (looks like someone already did that :( )

thank you for responding.. this forum is not as active as I was hoping... it since that you mentioned some ideas.

Stock engine cover will not work with the Kinetix plenum without a good amount of trimming. The only cover I'm aware of that will fit the Kinetix plenum is the Kinetix cover you linked from Z1.

Oh sweet i'm glad you're getting it all sorted out. Sounds like the previous owner was doing some crazy stuff when installing them....lol Yeah i've been a bit disappointed too, I have a subie also and have been apart of the nasioc forum for a long time so i'm used to a super active community.