How to write the notice that car washing in winter will not increase the price?

The notice of no price increase for car washing in winter in car wash room can be written as follows: Dear new and old users:

Thank you for your strong support to our store. In order to give back to you, when winter comes, all people who come to our store to wash the car will enjoy preferential treatment, otherwise they will be charged according to the summer price. Welcome to visit, thank you!