2017 seatbelt extender for 4 Touring

According to Toyota’s FAQ answer (“How can I get extra length in my seat belt?”), your Toyota dealer should be able to provide one at no charge, but it has to be fitted to the intended user, vehicle, and seating position.

 

Yup, they are free from the Toyota dealer. You have to "demonstrate" you need one, but if you do they are free.

 

It’s not just to prove the need, but also to determine the length: 6, 9, 12, 15, or 18 inches. From Toyota’s Seat Belt Extender Worksheet (TS-TR-SBE-0002-D, available by subscription to techinfo.toyota.com):

DIRECTIONS FOR DETERMINING PROPER EXTENDER LENGTH​

1. Place the seat in the position the applicant normally uses.
2. With the applicant in the seat, wearing the thickest coat expected to be worn, pull belt all the way out and try to buckle belt.

• If belt latches into buckle and feels comfortable against upper chest area, an extender is not needed.
• If belt does not buckle, continue with Step 3.
• If buckle latches but belt has no slack remaining, continue with Step 3.​

3. Measure distance between applicant’s navel and seat belt buckle (Dimension A) and enter on Worksheet.
4. With belt all the way out, measure distance between latch tip and buckle tip (Dimension B) and enter on Worksheet.

NOTE: If belt latches but there is no slack enter zero as Dimension B.​

5. Subtract Dimension B from Dimension A and record number in Check Number box on Worksheet.
6. Seat Belt Extender length is Dimension B rounded up to next extender length (without exceeding Check Number).

NOTE: If extender length exceeds Check Number, an extender cannot be provided to the customer.​

For more pleasant and accurate measurements, I’d suggest bringing a tailor’s soft tape measure (or even a paper tape measure like those given away at IKEA stores) with you to the dealer, in case they have only a steel rule or convex tape measure.