No matter the condition of your 1978 Bonneville, OPGI has the Cooling & Heating products you need to boost performance and get you back on the road. We currently carry 79 Cooling & Heating items to choose from for your 1978 Bonneville, and our Price Match Guaranteed prices range from as little as $6.74 up to $1,409.99. OPGI offers Maradyne plus eleven other trusted brands of Cooling & Heating products for your 1978 Bonneville, to help you find quality parts you can rely on. With OPGI's 45-day return policy and thousands of customer reviews, you can shop with the utmost confidence. Enjoy parts delivered directly to your home, or visit our sunny Southern California Showroom & Warehouse to check out our Cooling & Heating items in person.