Ending today, Groupon offers this Set of Faux-Leather Car Seat Covers in seven colors (Black/Blue pictured) for $34.99. Coupon code "TRIPLE" cuts it to $31.49. With free shipping, that's the lowest total price we could find by $18. It includes two front seat covers, split rear-seat left and right cover, one steering wheel cover, and four seatbelt pads.
Of note, this coupon is valid for up to three uses.