A quick Google shows that unit was released in the early 2000s and only has a 3.8 inch display. It must have not been very popular, there's hardly any info online about it.
My guess is it's not flash based like the Nuvi models, and it can't be updated in the same fashion. If the Garmin software says it's up to date, they're pretty much the final word.
Keep an eye on an Amazon website called woot.com - they often have refurbished Garmin in the 5 inch size for under $100, and they include 'lifetime' maps and traffic.