how bad is spraying water directly at rotors?

[Eos]

IMO it's completely fine. I would be more annoyed/worried about calcium deposits on the paint from when the water dries.

.........And I know you already said it, but change the sprinkler heads to the type that deflect from the driveway. They exist and usually aren't expensive. Your car is more important than the grass

I only wash the cars with irrigation (river) water to avoid any hardness the city water contains. After the first wash of the car there was some large drops accumulated on the flat part of the bumper under the trunk after I dried it, and then moved it into the garage. What was previously water stuck in the trunk gasket and heading downhill, is now water draining out. Anyhoo, the droplets dried and left circles of whatever chemicals are in the water.

No more. The irrigation water might be full of tiny seeds, but no more spots.

 

[Ferzerp]

It depends on the strength of the wheel. I'm surprised a high-end Mercedes would have that many issues.

Working on Infinitis for over a year, I never saw a bent stock wheel. Not once. Highly unusual given how many bent aluminum wheels I've otherwise seen. That's not fanboyism or anything; they just apparently engineer their big wheels (19's on 'sport package' type G's) REALLY well. I think they're all forged and most are made by Enkei. For whatever that's worth. I just remember finding it to be a really curious thing.

I have forged ones made by alcoa, and I am extremely paranoid about potholes. 255/45r20 tires.

 

[jlee]

It'll be fine...

 

[Ferzerp]

I only wash the cars with irrigation (river) water to avoid any hardness the city water contains. After the first wash of the car there was some large drops accumulated on the flat part of the bumper under the trunk after I dried it, and then moved it into the garage. What was previously water stuck in the trunk gasket and heading downhill, is now water draining out. Anyhoo, the droplets dried and left circles of whatever chemicals are in the water.

No more. The irrigation water might be full of tiny seeds, but no more spots.

typically calcium

 

[Fenixgoon]

you'd need to get the rotors pretty damn hot to truly "quench" them and change the material properties. not saying it can't happen, just saying that you're probably worrying too much.

if you just came off a racetrack and hosed them down, that might be cause for concern (since the rotors are designed to air cool). but otherwise, i cant imagine you'd have a problem.

 

[nerp]

You need a wall that rises from the ground when the sprinklers are on and then sinks back down when off.