Joseph has maybe the best answer. Let me explain: The catch is cars like the Gen 1 and 2, 4.7L Durango, and the recently discontinued, mechanically superior, less expensive Dodge Avenger were all discontinued because they were less expensive (Avenger) , mechanically superior (Durango and Avenger). The public desire for them destroyed other sales, especially more expensive less desirable new products.
Forever? The key is being handy, understanding basic auto mechanics, be able to do your own routine maintenance, if not more, and having a solid vehicle frame, treated every 4 years with a new blasting, rust neutralizing inhibitor, and sprayed with a synthetic "rubber like" shield. A strong thick frame is essential, , aka my 2002 Dodge Durango, 242K miles, and now, Nov 1, 2015, faster and greater towing torque/capacity, finally, 2-3 miles per gallon more efficient than when it was born...when I brought it. I haven't made a payment on for 9 years. I have, however, averaged an equivalent $75 a month ($900 in maintenance every year) and I have tools, and fortunately understand cars, and their repair. Your question, let me ad, the changes synthetic lubricants have given us are awesome. Checkout 'AMS Oil' and Mobil 1. They virtually eliminated internal wear, both in engine, transmission, transfer case, and differentials ( change every 5K to reap those rewards).
Designers are only paid to design new things, and support new car sales folks, and don't care about total revenue, they just want to make new, "innovative" floor models to support their salaries. The Avenger could have made Dodge an icon, if they were more secure and not threatened by it.