I had a Tyvek cover for my Audi and it lasted less than a year. Its
very light and packable but useless in the sun out here in CA. Mine
also started to shred at the seams from the wind. That said, $40 for a
homemade cover once a year is dang reasonable.

I've tried just about every brand and material of car cover in the
last 12 years and so far the best is a custom made polyester cover.
Something close to Cordura backpack cloth that a friend with a
surfboard bag company made for me. Its going on its 5th year of year-
round abuse here in the SF Bay Area. I ripped it recently putting it
on my Syncro which tells me that the sun has done its damage and
rendered the cloth thin and rippable. 5 years is very good for a year-
round cover.

Jeff in Marin

On May 27, 2011, at 2:11 PM, Automatic digest processor wrote:

> Date:    Fri, 27 May 2011 11:10:16 -0600
> From:    Tom Buese <tombuese@COMCAST.NET>
> Subject: Re: Thoughts on tyvek (westy cover)
>
> On May 27, 2011, at 10:40 AM, Chris S wrote:
>
>> Got pics?
>> =20
>> Since it holds water, are there issues with vapor breathability?
>> =20
>> I heard of hikers using tyvek to insulate their tents in the
>> winter.=20=
>
>
> Tyvek is a breathable house wrap used to allow any vapor migration
> from =
> the warm side, usually the inside, to the outside. I think it should
> be =
> a very good/inexpensive material for a car cover, unlike a plastic
> tarp =
> or Visquene.  A vapor barrier like foil or plastic is placed on the =
> inside to keep vapor from traveling into the insulation where the
> dew =
> point usually occurs & condensing in the insulation/wall. The house
> wrap =
> allows moisture to pass out but not in because of the warm to cold
> path =
> that vapor takes.
> Now if it is warmer outside than inside, the path would be reversed,
> but =
> at that point, I don't think the dew point occurs in the insulation
> so =
> no condensation? Someone help moi here?
>
> YMMV,
>
> Mr. BZ-on outside of tent only?