At Parts.OlatheToyota.com we offer genuine OEM Toyota Parts, and we think it's really important to understand the difference between a genuine Toyota part and a cheap copy.
1) Genuine parts are built to factory standards. When you buy an official Toyota replacement part, you're buying the same part that was put in your Toyota at the factory. That means that Toyota engineers specified all the characteristics and components of the part to ensure they would meet Toyota standards. Most after-market companies do not have the same strict set of standards.
2) Genuine parts are guaranteed. Depending on the replacement part or accessory you buy, you will be given a warranty and quality guarantee.
3) Genuine parts are going to last. After-market replacement parts are sometimes cheaper than genuine Toyota parts, but there's a reason for that. Buy nice or buy twice.