My trunk won’t stay open on its own any more, has anyone had this?
There are no dampers I can see just some strange metal rods that cross sides.

 

The bars are called torsion bars, when you close the trunk it twists the bars which puts pre-load on them. So the next time the trunk is popped it releases that potential energy and raises the trunk lid. So these usually last the life of the car so I would make sure they are all connected correctly and in the right spots. I had this same issue on my previous car which was a 04 Acura TL and my issue was the plastic clip that attaches the bars together at the point where they cross. Let me know if you find the issue and what it was👍🏻

 

checked the plastic clip in the middle and it’s all good.
If I force the torsion bar further back by hand it holds. Do you think the bars could be stretched?

 

The next step would be to take a video of the trunk closing from the inside using a camera pointed up to check the action of the torsion bars. This is the method I used to find my problem. I just used my phone on video with the flash light turned on and was able to see what the problem was. Also, check youtube and from what I can remember I also watched some videos to educate myself about how these operate.

 

Remove the trunk liner on the driver side you will find two holes for torsion bars. More it to the next adjustment hole and this increases the tension. I had to do this when I bought my car, had the same problem.

 

See this post it will fix your problem:

https://www.clublexus.com/forums/gs-...l#post10519685

 

Some cars have a optional higher tension Rods you buy when you add a Spoiler due to the extra weight.

So looks like Lexus gave the extra tension hole for you to add tension by moving the Rod, correct?

 

Correct. The adjustment is to compensate for the added weight of the oem spoiler.

 

Hey I see you added the Lexus Spoiler. I am in the process of doing this too. What trick did you use to make to install and drill holes in the correct place? There is a template for the bigger Lip Spoiler but I could not one for the F Sport one?

 

I don't think there is a template for the f-sport one. You could avoid drilling holes all together, remove the clips and just use 3m VHB tape to mount it. Otherwise put a mark on the tips of the clips set the spoiler down and it will marks the sports, not sure how good that works.