The oldest trucks we have that use Adblue are ten years old, so in the truck world it's been around for a long time. We don't generally get many problems with the Adblue systems, the Iveco's are probably the most problematic. The only car we've got is not quite two years old, it's a Discovery Sport and we've had no issues with that.
From what I understand the cars don't need topping up with Adblue very often, with the trucks is one tank of add blue to about 3 tanks of diesel I think - it's not something I generally get involved in. It's also very common to find Adblue at filling stations, and I believe some even have it on pumps.
Adblue can crystallise when exposed to air, and this can cause blockages, but other than that it all seems to work OK.
How much mileage do you generally do, and how long is your average daily run?
Modern diesels have DPF filters, these need to get up to a certain temperature to self clean, many people have found that these block up quickly because they are only doing low mileage short runs. If this is the sort of driving you do then a petrol or hybrid will suit you better, and a petrol car will probably be cheaper to start with.
PS. In ten years I'm only aware of one truck driver putting Adblue in the wrong tank, or was it diesel in the Adblue tank. On the car we have I'm pretty sure it's under the bonnet, so unlikely to get diesel in it, but I suppose oil or water could be put in by mistake.