GrahamG

Very helpful Brian, thanks for taking the trouble to post. If I had done this and tackled the rear sub frame area my superb LS400 would still be mine. Had the idea that if the wheel arch liners were removed a bung might be exposed offering access to the double skin wing voids. However a 10mm hole is not the end of the world. Some cars have more than one sill cavity e.g. two separate parallel 'tubes'. If anyone can add any more specifically for the LS430 it will be appreciated.

Have just bought a 2004 LS430 with 82,000 miles to replace a 1995 LS400 which sadly and perhaps unnecessarily died of the rust. After hours here and elsewhere researching how the LS430 rusts [including the dreadful door and boot failures] here goes my first post on the forum. Have access to a commercial garage including compressor and will probably use the Dinitrol products simply because of less smell in what is meant to be the wife's car. Any advice please how to gain access to the door sills? Can the black plastic mouldings on top of the sills [with the 'Lexus' motif inset] be levered/popped off to allow a way into the sill void? The wings are double skinned and need a way to get a flexible spray wand in there. Is it straightforward to remove and reinstate the plastic wheel arch liners? Any advice about corrosion proofing this particular model will be appreciated.