I havn't seen a Ferrari break down in the middle of the road... have you? I highly doubt a Toyota is more reliable than a Ferrari, the engineers take extreme care in assembling a Ferrari, same can't be said for a Toyota...
Also one would expect a Ferrari to last well over 10 years, vintage Ferrari cars costs a fortune, whereas Toyota cars tend to be turned into scrap metal.
Have you considered that the plastic casing is required? If you replace the W4 with a metal casing will definitely cause strong resonances, without the plastic dampening the reflected waves, it will be a nightmare to work with. Since you can't fit the contents of the W4 into MH1c, and you can't just fill the casing of the W4 solid, there is not much you can do to make it feel more durable.
a bit off topic but more expensive cars does not necessarily equal more reliable
japanese cars have topped the ratings in reliability for a long time
rebutting your point, ferrari car owners tend to take better care of their cars then toyota owners
regarding build quality, i think it varies
sometimes more r&d money goes into build quality
but some instances, quality control is really bad- eg. the lower end ultimate ear iems are notorious for failing quickly