The dealer had offered me the same thing when I purchased my X.
" Perma-Plate: protects your paint structure from sun and other environmental damage using high-tech Teflon-based hard shell coating-- Perma-Plate is "Permanent" protection that never washes away like wax does! Boost your resale value and enjoy a vehicle that is easier to maintain! LIFETIME WARRANTY OPTION on new vehicles." Basically, if you are too lazy to wax your car from time to time, you should spend money on this. BUT, if you are the person to remember to wax, then it's really not necessary... so if you have the extra cash to spend, then go for it.
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Cloud9
Southern Cali
Cloud White
'01 Xterra XE 4X2 V6