Non-petroleum based grease on the seals can help...if you make sure they are clean. Don't forget the firewall grommets, etc.
Grit, wee pebbles, weeds, etc, can create an opening for leaks.
If you keep moving, you are less likely to leak.
If your windows are closed, there is better pressure to keep the water out...open the windows, and the water comes in faster.
If your floor plugs are in, etc, you are less likely to leak.
If you go too slow, you leak, if you go too fast, you leak.
Pot the ECU, and it can get wet btw.
TJ's Build Thread
2001 Xterra SE, 2003 V6, 5 spd, Shrock Sliders, Bumpers and Skids, Warn 9.5xp Winch w/125' MasterPull II, OBA w/4Gal Tank & 4 CFM Compressor, Revolver Shackles, Deaver 3-Pack + Calmini 2-Pack + OEM Leaves, Bilstein 5150, SLR UCA, Diff Drop, 3" SL, 2" BL, 33x13.5/16 LTB's, Snorkel, Electric Fan Swap, etc...