Is there any way to replace the stock nav system with something that is easier to use and more up to date and works? I did upgrade the disc and it's still a pain to use. My Iphone does a much better job, is easier to use. Also can anyone give me advice on upgrading the stock suspension on a 2003 SC 430, I got it a couple of months ago with 24000 miles but would like better handling but would like to keep the ride decent. Thanks

 

Two options I can think of off the top of my head.
1. Upgrade to the GEN 4 system ( you current have a stock GEN 2/3 system) which a straight swap out of the NAV ECU hardware. You'll also need to purchase a new GEN 4 DVD. Lexus did NOT put GEN 5 systems in the SC430s and the newest GEN 6 only works if you rewire the car.
2. Upgrade the stereo HU with one that includes NAV and abandon the Lexus OEM one.
But since you said your iPhone is simpler to use and does a better job, why would you ever consider doing it.
I've done both upgrades.(no NAV in the HU I was happy with the GEN 4 system.

 

Regarding the suspension question...there are endless discussions on the topic...may I suggest using the Advanced search feature of the forum..you'll find it under the Search menu item near the top. In advanced search you can limit your search to this forum only or multiple one, and search on a key word or phase which narrows the responses. There are as many products as opinions so it will up to you to do some due diligence. Good luck with your search for information.

 

^I purchased TTE springs, the TRD front sway bar, Daizen Bushings for the rear sway bar, LCA, steering rack and a Cusco strut tower bar and the car handles great for me now. It probably would have been easier cheaper to get coil overs but it was all done at different times so if I could go back I would just have gotten coilovers or air ride and called it a day.