Almost overnight my MX5’s paintwork devolved cloudy patches

[TurboD]

Looking for advice please from anyone who has encountered something similar to my rather strange situation. I had to move my convertible 2004 MX 5 out of the garage for a few days so I covered it with a heavy duty car cover I ‘d bought a year previously from Halfords and which had been lying around in the garage also. Three days later when I removed the car cover to drive the car back into the garage I found that a number of milky/cloudy patches had developed on the car paint work.
I’ve been racking my brains as to what could’ve caused this and the best explanation I can come up with is that our cat has peed on the inside of the car cover and this has then reacted in some way with the car paintwork. The lacquer layer seems to be completely intact and as far as I can see the discolouration is with the paint beneath the lacquer.
I have tried Autoglym Super resin polish which was recommended to me by a guy working in Halfords (not sure if this was actually ever going to work) but it made absolutely no difference to the discolouration. Wondering if there is anything else that I could do or if I’m just going to have to accept that a re-spray is the only solution?

Any thoughts or advice would be greatly appreciated.

[finlo]

Try a hairdryer on it.

[ro250]

There was a similar question on the Detailing World forum recently. Was diagnosed as water which needed drying out - have a read:

https://www.detailingworld.co.uk/forum/showthread....

[trickywoo]

Lots of theories about why this happens but essentially you have moisture under your paint. Whether it was already there from a previous paint job and the cover helped it come out or the cover itself has put it there you may never know.

Unfortunately chances are you either live with it or get it repainted. Heating it is of course worth a go but don’t have your hopes too high.

[LennyM1984]

Car covers do more bad than good in my opinion. As others have said, this is moisture that has been held against the paint by the cover and leeched into the slightly porous clearcoat. Direct sunlight will eventually clear it up but you can try to help it on it's way by spraying the area with IPA.

[mbwoy84]

Agreed. Moisture in the paint, which the car cover has caused to break out.

[TurboD]

Folks
Many thanks to all of you who took the time to reply to this query. Incredibly helpful information. I did try the hairdryer but after about 15 minutes I gave up as it was making no difference. I’ve resolved to take it to a body shop tomorrow and let them have a look at it. Depending on what they say I may try some of the other options such as leaving it out in the Sun. My worry would be that, relative to the value of the car, a respray would be silly money.
Thanks again.
Turbo D

[fourfoldroot]

The paint on my Triumph is quite soft and if it gets droplets/beading rain on it,then strong sunlight, it gets marks like that. Cutting compound/t-cut gets it out. Then rewax . Possibly the automglym doesn’t have enough cutting power. Have a try, nothing to lose if it’s going to need a respray anyway.