[Svet]

Mine is a daily driver and I know these cars don't rust much, but on the e90 m3 for example, the rear subframe can and does rust.

I'm curious what some of you guys are doing?

[Albator_IIII]

Originally Posted by Svet

Mine is a daily driver and I know these cars don't rust much, but on the e90 m3 for example, the rear subframe can and does rust.

I'm curious what some of you guys are doing?

I wouldn't do any. I was explained that BMWs have something applied during the manufacturing and doing any additional rustproofing could interfere/work against the original stuff.

I have had my E90 since spring 2008 as daily driver year-round, never did any rustproofing and the body still looks fantastic.

Mind you, I do not live on the East where there is more humidity and salt in the winter.

[German1967]

Nothing to do. All sheet metal is galvanized.

[Tag]

M cars have all aluminum suspension components.

[JustinHEMI]

Parking mine for winter.

[RockCrusher]

Originally Posted by Svet

Mine is a daily driver and I know these cars don't rust much, but on the e90 m3 for example, the rear subframe can and does rust.

I'm curious what some of you guys are doing?

While I can leave my M2 parked when the roads are bad with snow/salt at other times with other cars I have done nothing.

Since my 2002 Boxster my Porsche cars have come with special paint on the sheet metal of the bottom of the car. It resembled an epoxy based paint I came upon years earlier I think on motorcycle frames.

Very durable paint. The only care it required was care in lifting the vehicle. The dealer service bay lifts had rubber pads on the lift plates to avoid marring this paint.

I drove this car in winter and when the temperature was above freezing and the roads dry I treated the car to a rinse at a DIY car wash. I'd rinse off the salt and any accumulated snow/ice/slush. Then I'd drive the car and use the brakes enough to be sure they were dry.

Might add that the car came with a coating of cosmoline on exposed metal running gear, engine, transmission.

So too did my 2008 Cayman S. No pic of the Boxster's undercarriage but I have some pics of the Cayman's. See attached pic. The brown stuff is cosmoline or something like it.

Have to point out most of the exposed metal under the car is aluminum.

Had a chance to look at my M2 while it was on a lift at the dealer while the car was getting a tire repaired. Did not see any signs of cosmoline. Unfortunately I didn't look to see what kind of underbody paint treatment the car had. Since I have no plans to use the car in bad weather it was not a priority to see what rust proofing protection BMW provided.

[AdnanH35]

I wouldn’t worry about rust on these new BMWs. I live in the Northeast and daily drive my cars in all sorts of weather. 150k miles on a F30 335 and 100k on a F80 m3, no signs of rust

[Carefree]

Nature’s rustproofing-Arizona.

[AZG87]

Originally Posted by Carefree

Nature’s rustproofing-Arizona.

Unless one gets trapped in water on one of the random freeway floods during a monsoon