George Eberhardt writes:

As far as I can see, the installations are so bad
that there is no point in paying for insulation.

Yours is a typical misunderstanding.

Garages are cost-effective because they control humidity, not temperature.
The real enemy to your car is a condensing atmosphere, which a garage
mostly eliminates, even if unheated and even if uninsulated. Ordinary jamb
seals and panel seals work fine to eliminate infiltration of damp outside
air.

The amortized cost of a garage is less than the amortized cost of corrosion
to your ungaraged-vs-garaged car, for typical cases of "garage" and "car".

So it typically *costs* you money *not* to have a garage.