98s have drain holes in the front corners that can get clogged and then you will get water in the cab. I used a air compressor to blow them out and no more leaking. This is a good moonroof they only leak if the drains are clogged. They are actually kinda hard to find if they are clogged, but poke around and you will find them.

 

There are 2 more drain holes at the rear corner. What front 2 are clogged means that the rear 2 are also so. Below link might help you to clean those rest of 2.
https://www.clublexus.com/forums/ls-...l#post10064243

 

Using shop air at 150 or more psi is too much pressure I regulate it to under 20 psi for blowing them out, especially the rear ones as you sure wouldn't want the hose either blowing up or coming off the plastic catch tray. I think some folks have used weed eater line to run down them as well. The only easy way to access the rear drains are the ends of the tubes or hoses in the trunk and then of course your just blowing the clog back into the tray, just a heads up. But it clears them and as long as the roof seals are working there should be little to nothing for water entry.

 

weed eater line another great idea!