Is there an easy way to clean a fabric roof lining? There are some marks and stains on mine and I think a previous owner also smoked. I am thinking of buying a steam cleaner for the house and I was wondering if this would be something that might work but I dont want to get anything wet under there as my dashboard is likely to light up like a Christmas tree with all sorts of error messages and I will end up wishing I had left well alone. Any ideas?