You can buy the same warranty from other Toyota dealers anytime before you reach 3 year 36k end of bumper to bumper warranty. It costs about $900 from one of the dealers who sells on here. That price includes about $2,000 of profit for the dealer.
This is the price chart I was given about a year ago. I can put you in touch with the dealer if you're interested. I have no affiliation with them other than having bought my warranty though them. It's the Toyota Care Platinum warranty - from Toyota. No aftermarket stuff.
Here are all of the term and mileage combinations:
Plan Code 4RUNNER
3YR/50K B35 $ 390
3YR/80K B38 $ 435
4YR/65K B46 $ 450
4YR/100K B40 $ 575
4YR/125K B41 $ 690
5YR/60K B57 $ 450
5YR/80K B58 $ 500
5YR/100K B50 $ 665
5YR/125K B51 $ 815
6YR/75K B67 $ 545
6YR/100K B60 $ 795
6YR/125K B61 $ 1,040
7YR/75K B77 $ 615
7YR/100K B70 $ 925
7YR/125K B71 $ 1,150
8YR/75K B87 $ 735
8YR/100K B80 $ 1,045
8YR/125K B81 $ 1,405
9YR/100K B90 $ 1,265
9YR/125K B91 $ 1,665
10YR/100K B95 $ 1,360
10YR/125K B96 $ 1,795