
I am not and would not be concerned with safety issues involving washer fluid, but my opinion changes at 50/50 water/meth mixes and above, especially pure meth. As others have pointed out, meth is a fuel and should be treated as one (i.e.: stored inside of a fuel cell, not a windshield washer bottle).
In addition to our own safety, we must consider that of the workers that come to our rescue.
Some info on methanol:
4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION
4.1 Human health hazards, prevention and protection, first aid
Methanol vapour and solutions are irritating to the skin and
eyes. Prolonged or repetitive skin contact can cause dryness, cracking
and dermatitis.
Methanol is well absorbed by the inhalation, oral and
percutaneous routes and can cause metabolic acidosis and damage to the
central nervous system, optic nerve, retina and liver. The onset of
symptoms may be delayed following exposure (see Summary of Chemical
Safety Information, section 6).
4.2 Information for physicians
Full information on the diagnosis and treatment of methanol
poisoning is contained in the IPCS Poisons Information Monograph
No. 335.
Thorough and vigorous washing of the skin with water will
minimize systemic absorption following skin contamination. Gastric
decontamination should be considered if the patient is seen relatively
early (e.g., within one hour after ingestion).
Following ingestion, effects may be delayed and it is important
to keep the patient under observation. The treatment of poisoning is
based upon the use of ethanol as antidote, haemodialysis and
correction of acidosis (by bicarbonate administration). It is
recommended to contact urgently the nearest poisons information
centre.
4.4 Explosion and fire hazards
4.4.1 Explosion hazards
Methanol vapour/air mixtures are explosive. Violent reactions of
methanol can occur with oxidizing agents (see section 1.2).
4.4.2 Fire hazards
Methanol is highly flammable and burns with an invisible or light
blue flame. Methanol may be ignited by heat, sparks or flames and
vapour may travel to a source of ignition and flash back.
4.5 Storage
Methanol should be stored in clean containers made from either
mild steel, stainless steel, high density polyethylene or vulcanized
natural rubber. Unsuitable container materials include zinc,
aluminium, magnesium, magnesium alloys, lead, tin, titanium,
plasticised PVC, polystyrene or polymethyl-methacrylate. Storage
tanks should be constructed with an internal floating roof and an
inert gas pad to minimize vapour emissions.
Methanol should be stored in well-ventilated areas away from
direct sunlight and moisture. It should not be stored with oxidizing
materials such as perchlorates, chromium trioxide, bromine, sodium
hypochlorite, chlorine or hydrogen peroxide, owing to fire and
explosive dangers.
Because of the flammability of methanol, storage tanks should be
enclosed by a dike and protected by a foam-type (either carbon dioxide
or dry chemical) fire-extinguishing system.