I do not understand what do you mean by 'escape' (like in C# string \n\r?), but XmlSerializer converts special characters to it's entity value automatically, otherwise it would not be a valid XML...
UPDATE
You have to understand (and explain the customer) that quotes and double-quotes are legal characters in XML, that's the reason the serializer do not touch them...
The only options I can see is writing your own serizlizer:
IXmlSerializable Interface (System.Xml.Serialization)[
^]