BMW Z4 Roadster 3.0i 2005 - Manual (Page 18)

If your car is driven only for short distances of
less than 10 miles over a prolonged period of
time, without an occasional drive at highway
speeds, the engine’s charging system will not
maintain the battery. Insufficient use of the
vehicle could result in short term starting
problems and in the long term could damage
the battery.
In case the car is not operated for more than
four weeks it is advisable to:
a) consider using a proper trickle charger,
following the charger manufacturer’s
instructions, to maintain the battery’s state of
charge; or
b) consult your BMW center regarding battery
removal. Once removed, the battery must
be charged and stored in a cool, dry place
where it can be protected from freezing. If
the battery will be stored for over 3 months,
it must be recharged every 3 months, or
else it will become damaged and useless.
Please consult with your BMW center for
further guidance and information.
Corrosion Protection
Extensive corrosion protection measures
implemented by BMW now make it possible to
offer a twelve-year limited anti-corrosion
warranty against rust perforation on your
vehicle provided that the vehicle is maintained
in accordance with the provisions of the New
Vehicle Limited Warranty as outlined in the
Warranty Section of this Statement (page 29).
The major degree of corrosion protection is
due to the electrophoretic dip painting process
which cathodically deposits paint particles on
all body parts, attracting paint particles into the
minutest cavities or seams. Body parts are
designed to provide optimum corrosion
protection.
During manufacture, exterior body parts
receive an additional corrosion protection coat.
Hood, trunk, doors and other body parts with
metal folds are coated with PVC and sealed
from the outside.
All floor panels receive a resilient coating of
PVC for maximum protection against damage
due to stones, etc.
Corrosion protection materials tested over
many years are applied to the surfaces of
cavities and to the entire underside of the
vehicle during and after assembly.
Requirements for maintaining the twelve year
unlimited mileage anti-corrosion warranty are
outlined in the Warranty Section of this State-
ment (page 31).
Restoring corrosion protection
Please take care that anti-corrosion material is
replaced when your car is repaired after body or
chassis damage.
BMW will not accept any liability for any parts
and accessories not approved by BMW.
Underbody maintenance
The underbody has to be cleaned at least once
a year, in spring, with plain water in order to
remove mud, chemical sediments and other
deposits. If those materials are not removed,
corrosion (rust) will occur.
Your BMW center will do this anti-corrosion
service for you.
WARNING
Do not apply additional undercoating or rust-
proofing on or near the exhaust manifold,
exhaust pipes, catalytic converter or heat
shields. During driving, the substance used for
undercoating could overheat and cause a fire.
Battery Care
14