Hello,
I was checking the specifications at this site:
http://www.motorola.com/Business/US-EN/Business+Product+and+Services/Mobile+Computers/Vehicle-mounted+Computers/MW810+Mobile+Workstation_US-EN#
However I am not sure if the system you are using is in fact using the Intel® QM77 or the Intel® GM45 chipset
If the system is fairly, most likely will use the Intel® QM77 chipset, so try using the zip files for Intel® Rapid Storage Technology 11.7 available on this URL:
http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=22194&ProdId=2101&lang=eng&OSVersion=%0A%09%09%09%09%09%09%09%09%0A%09%09%09%09%09%09%09&DownloadType=Drivers
If it is an old system that could be using the Intel® GM45 chipset, then try an older version of this software, version 9.6 available at:
http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=15251&keyword=9.6&DownloadType=Drivers&lang=eng
Keep in mind that Microsoft* Windows* XP requires those drivers to be loaded through a floppy. You may use a USB floppy but it needs to be listed on Microsoft’s web site as compatible. Refer to http://support.microsoft.com/kb/916196/en-us for more information on compatible USB floppies.
You can also use nLite as you did, just make sure to extract and put all the files in the installation CD you are creating