A container (1, 20, 30) for a fluid in a vehicle, comprising: an inlet for filling the fluid into the container, the inlet being arranged at a top wall or top edge of the container, the inlet being adapted to couple with a cap for closing the inlet, the cap comprising a valve for pressure equalization; an inner wall protruding from around the inlet into the interior space of the container, thereby forming an air trapping volume for trapping air; wherein the air trapping volume is delimited by the inlet, the inner wall, the cap and a fluid surface inside the container when the container is used; wherein the inner wall is configured such that the cap and/or the valve remains separated from the fluid by the air trapped in the air trapping volume if the fluid surface is inclined about an axis, wherein the inner wall separates the interior of the container into a first and a second container portion (13, 14), the first and second container portions (13, 14) being communicatively connected to allow a flow of fluid there between, characterized in that the container (1, 20, 30) comprises a conduit for communicatively coupling the first and second container portions (13, 14), the conduit comprising a conduit mouth to allow a flow of air between the first and second container portions (13, 14) when the conduit mouth is not covered by the fluid, wherein the designated maximum filling level of the container (1, 20, 30) corresponds to an amount of fluid in the container (1, 20, 30) having more than 75% up to 90% of an inner volume of the container and lies below the conduit mouth such that the air flow is at least allowed in the container's rest position. an inlet for filling the fluid into the container, the inlet being arranged at a top wall or top edge of the container, the inlet being adapted to couple with a cap for closing the inlet, the cap comprising a valve for pressure equalization; an inner wall protruding from around the inlet into the interior space of the container, thereby forming an air trapping volume for trapping air; wherein the air trapping volume is delimited by the inlet, the inner wall, the cap and a fluid surface inside the container when the container is used; wherein the inner wall is configured such that the cap and/or the valve remains separated from the fluid by the air trapped in the air trapping volume if the fluid surface is inclined about an axis, wherein the inner wall separates the interior of the container into a first and a second container portion (13, 14), the first and second container portions (13, 14) being communicatively connected to allow a flow of fluid there between, characterized in that the container (1, 20, 30) comprises a conduit for communicatively coupling the first and second container portions (13, 14), the conduit comprising a conduit mouth to allow a flow of air between the first and second container portions (13, 14) when the conduit mouth is not covered by the fluid, wherein the designated maximum filling level of the container (1, 20, 30) corresponds to an amount of fluid in the container (1, 20, 30) having more than 75% up to 90% of an inner volume of the container and lies below the conduit mouth such that the air flow is at least allowed in the container's rest position.