Definitely too early in some respects - the LED boards were huge and clunky, advertisers weren't really interested despite the advantages (for a London bus, apparently, it took ~2 days out of service to replace vinyl adverts which is why you frequently see them with 6m+ outdated adverts), some questionable decisions were made re: software, etc.
There were rugged PC's available back then for automotive use (think cop cars and the like). To me it sounds like they did not spec the hardware properly or installed it improperly.
Yeah, there were two schools of thought - proper rugged industrial PCs or "whatever we can find cheap on $boxshifter.com". The latter cohort won (although not really because they were a constant nightmare of problems...)