I'll chime in with agreement on most of the points in this thread. My other car is a 2003 Subaru Legacy and even that has enough electronics to annoy me at times - the HVAC especially, but also the electronic auto gearbox is appalling. Fantastic Subaru build quality as you'd expect, but getting enough power out of the flat-6 is difficult because of all the electronics interfering. I would not want to own a new car where every action I make is second-guessed by a computer. In Dragon, whatever switch I flick does what it's designed to, immediately. Also with the Legacy, two things bug me - first, the interior lights have an option to come on and off with the door locks, but this is disabled on mine and only the dealer can enable it - I can't just flick a switch or enter a code. Two, I somehow lost one of the keys (believe me, I have no idea how) and am looking at a bill for $220 to replace it - a lot of that is for the blank key, then it has to be cut and programmed to the car's security system. All of which I have to do through the dealer.
Yes, there is a good argument for reliability differences in older cars, and I've experienced my fair share. I'm sure a few others keep a decent spares box in the car at all times (I keep a spare coil, for example). And yes, Dragon has broken down on me at inopportune times (burst radiator while out in France, for example). However, all the problems I've had, I've at least had the chance to fix myself. With absolutely everything computerised on a modern vehicle, the moment something goes wrong, the car will insist you limp it to a dealer to fix it. More often than not, the engine bay is covered in plastic which needs specialist tools to remove, or it's a software bug that requires a firmware update to fix. My father in the mid-2000s was granted a company car and chose a brand-new BMW 320dES; since he had to visit client sites, he put a lot of miles on the car, and it suffered greatly. No end of problems, many of them electronic. More than once, a technician had to 'reboot' the whole car because the huge network of computers (claimed to number over 70 ECUs because that's where they stop counting) came out of sync. Fortunately the company footed the bill for all the repairs, but it must've come to thousands of pounds in the 5 years he had the car, maybe as much as 1/4 the value of the brand-new car.
If a car as old as the mk2 suffers a problem, places like this exist to collate all information on repairs, and there are mountains of technical information, some directly from the manufacturer, that have been published. I've dug into the inner workings of the fuel injection system with nothing more than a multimeter, following the technical guides from Toyota. Trying to do that on a CAN-based car would require either a computer (and praying that the diagnostic interface is working properly) or an oscilloscope/logic analyser, both expensive options. Yes, advanced technology does have its advantages when it works properly, such as better fuel economy, tighter control of emissions etc., but it's so damned fragile that when you factor in the cost of repairs when (not if) it all goes wrong, you probably wind up with similar ownership costs.
Others make a good point about manufacturing new cars - even with mass production raising efficiency, just one new car involves a huge amount of cut/pressed/forged/welded metal, shaped plastic, wiring, fabric/leather... All of which requires fuel to be used creating it, then assembling. I'd imagine 50,000 miles worth of driving an older car is a conservative number for the amount of energy involved. Oh, and let's not forget, some of these cars are only built overseas and then shipped to the intended markets, and mass shipping is one of the least regulated causes of pollution ever. Ships burning heavy oil spew hideous amounts of pollutants, far away from any individual country, so there has never been any particular concern for them to be clean. Of course, building cars in factories in the local country is a lot more friendly in this regard.
Add to, older cars are not necessarily smog-producing gas-guzzlers. I'm sure a few people here know the mk2 can get a respectable 300 miles out of its fuel tank (inb4 Ray mentions ethanol gas...) and I'm pretty sure I can get closer to 500 with some effort. Heck, there's an old 1980s Ford Escort with a 1.6-litre diesel engine that can manage a huge 70mpg, a figure that VW's BlueMotion has only just managed to equal (although the less said about VW diesels, the better). CO2 emissions might be high, but the UK government has recently been forced to admit its encouragement for diesels in the early 2000s was short-sighted - diesels do indeed produce lower CO2 per volume of fuel, and with money flowing into the diesel market the technology has advanced considerably, but we're now learning that diesel exhaust contains nitrogen dioxide and fine particulate matter that is hazardous to human health, and extremely difficult to do anything about. At least to deal with CO2 we could in theory plant more trees. Well-maintained older petrols generally burn very clean (Dragon nearly meets the current standards for petrol exhaust cleanliness, within tolerance for hydrocarbons, off by about 0.2% for carbon monoxide); the worst that happens is it starts burning oil, at which point you either overhaul the engine, or throw it away. Diesels have a lot more problems with emissions than petrols, especially with things like particulate filters and exhaust fluids.
That said, nitrogen dioxide is also produced in petrols using direct injection - the higher combustion temperatures are what cause it. So, direct injection and ultra-lean burn might well reduce fuel consumption and CO2 production, but the tradeoff of this technological advancement is higher NO2 emissions that we cannot yet deal with; older port-injected technology might be outdated, but the cooler combustion chambers produce considerably less NO2. A case where improved tech may well be a step backwards.
There's a lot of reasons why newer cars aren't necessarily an improvement, even if the OP was trying to plug a second-hand dealership. I do have a particularly strong opinion because I work with computers, and can see first-hand how advancing technology really has had its drawbacks, and now cars are just computers on wheels.