It's very common for company to nego rate with Hertz to include LDW. My current job and previous job both have such contract. The LDW line item will say "included in rate" or something like that and there is no extra charge for it.
If your accounting department give you hassle for that, then send it back and tell him Travel negotiated for that inclusion and there is no way to split out. The auditor is very inexperience at best - this is very common.