I worry about the longevity of all the new techniques?
We all know plywood and MDF will fail in time. - especially if water gets to it.
what about UV stability. Hot sun. Life of plasticisers (sp) in the plastics, and resins that are used?
I wouldn't be too worried. UV and Ozone exposure will have an effect on plastics but the main short term affect is discolouration. I think the most common material would be ABS, with ASA and Nylon (PA6) filaments also availible.
ABS is what almost all plastic painted automotive body panels are made from, think bumpers, wing mirrors and the like. The natural colour will fade in UV, but a good coating of a quality automotive paint should protect it sufficiently for the lifetime of our models (or 100,000 miles).
ASA and PA6 are used bare for the black textured panels that are very common on modern vehicles. The colour will be a bit longer lasting, but still will be fine under paint.
I think LGB's plastic is Luran-S. Which is a brand name for a particular type of ASA.