Wash. Rev. Code § 46.16A.150
A person may not purchase a vehicle displaying foreign license plates without removing and destroying the license plates unless:
[ 2010 c 161 s 411; 1987 c 142 s 2. Formerly RCW 46.16.029.]
Effective date—Intent—Legislation to reconcile chapter 161, Laws of 2010 and other amendments made during the 2010 legislative session—2010 c 161: See notes following RCW 46.04.013.