I just picked up the car after the upper control arms were changed along with the rear axle carrier bushes.
It's made such a big difference. The car feels so tight now, and much more responsive around roundabouts etc. The old arms were quite worn out and the same with the rear bushes. Only point is that the factory rear bushes are normally rubber (which cost a small fortune to replace), and my replacements are made out polyurethane. This has the effect of making the ride much firmer in the back(more like a German car), but the upside is that they don't wear out like rubber, and the car handles much better.
Price if I didn't do my research = £1,900
Upper control arms bought in UK and fitted (£800 parts, £100 labour)
Complete rear hub units (£1000 parts and labour, so I've been told)
Price I paid (includes shipping cost from States) = £570
Upper control arms bought from USA and fitted (£300 parts, £100 labour)
Rear axle carrier bushes bought from USA and fitted (£50 parts, £120 labour)
I hope this helps other owners of older LS400s. It's definitely a result for me.
I'll give more feedback about the bushes once I have driven the car on different types of roads.
Pops - did you ever find out if you have the same issue as mine on the rear bushes? One of the symptoms is that the car will "jump" at bit from the back end when driving over a bump on a bend, plus the rear will feel twitchy too even on straights.
Where I got the parts.
Email ozzis@bellsouth.net - John @ Ozzis automotive. Based in Atlanta, USA.
Phone 00 1 770-552-5280 ($46 for the bushes, plus $60 for UPS shipping)
www.lexus-parts.com (based in Texas, USA)
Got 10% discount by mentioning Lexus Owners Club
I contacted Darrel Diller on ddiller@sewell.com ($542 for both arms, plus $48 for shipping)