I recently purchased a beautiful 1999 LX470 with 120k in white. The paint is in great shape but it was not consistently waxed and NEVER clay barred. I used soap and water to strip all of the surface dirt, grime, and grease and went to town clay barring. I spent over an hour just doing the front left quarter panel yesterday and it looks great. I use half a megs wax bar flattened into a disc shape and make horizontal or vertical strokes over about 6 inches at a time until totally smooth and spot free. It's extremely effective but exhausting and time consuming. At this rate of a panel per hour, it will probably take me 12 or more hours.

*Does anyone have a more efficient way to clay bar a very dirty car?* Front driver's side quarter panel after thorough wash with soap, water, and wash mitt.
After an hour+ of clay barring

 

What are you using to lubricate the paint while clay barring? You can use spray wax or detailing spray, but I find it much easier and cost effective to use a bucket of car soap and water with a wash mit. It shouldn't take 12 hours to clay bar a car even using that method. Perhaps the build-up is too much in the paint and a powerful buffer with compound and polish is needed?

 

Spray Iron-X on the car while it's still dry and let it dwell on the paint for several minutes. respray again before first coat dries. Rinse thoroughly, preferably with pressure washer and repeat as necessary until most of the specs are gone. Any left over, hit it with a quick clay bar.

If you have tar specs or splatter, use a solvent like tar-x or tarminator or even 3m gen. adhesive remover to remove first, then wash the car and clay bar.

 

As 97-SC300 mentioned, using specialized chemicals to remove contaminates can save you considerable time during the clay bar process.

I discuss the decontamination process in the following articles....

Explaining the Decontamination Process Part 1
Explaining the Decontamination Process Part 2

 

You should get a clay-bar holder, makes life a lot easier.

For a big car like this that was never clayed, I would keep 2 clay bars on hand. You can keep folding them into a ball and flattening them out when they get dirty, but at some point, it's best just to go to the next bar.

I usually wash the car with car shampoo and then start claying with clay lube, host everything down, wash it again with the mitt and hose it down again. Did a 1998 Camry like that last week and it worked great.