I've thought about the stronger springs, but over time they weaken too, and besides, if you don't have a proper spoiler on the back, they're far too powerful - hard enough to crack the rear screen if you were parked on a hill........
There's also this from a while back........ [url="http://www.lexusownersclub.co.uk/forum/index.php?showtopic=33286&hl="]LINK[/url]
Having resurrected this idea, it's got me thinking about doing it again......just still not sure about doing things like drilling my back seat myself!