Asking a prosecutor what is and isn't legal is like putting a fox in charge of a hen house! They may be able to choose whether or not to prosecute an individual, but they don't have any authority to decide the legality of anything.
The intent of the legislature on this point for substitute amendment 2 of SB93 was clear and unambiguous:
From the "WISCONSIN LEGISLATIVE COUNCIL AMENDMENT MEMO on the Senate Substitute Amendment 2, as Amended" which was what the Joint Committee on Finance voted on and approved:
https://docs.legis.wisconsin.gov/2011/related/lcamendmemo/sb93
"The substitute amendment makes a number of statutory changes with respect to the placement, possession, and transportation of firearms in various types of vehicles, as follows:
- Permits placing, possessing, or transporting a firearm that is a handgun in a vehicle.
- Permits loading a firearm that is a handgun in a vehicle."
From the Milwaukee Journal Sentinel, "Wisconsin Senate passes concealed-carry bill":
http://www.jsonline.com/news/statepolitics/123826279.html
"The bill would also allow people to carry loaded, uncased guns in their cars. Now, guns are allowed in vehicles only if they are unloaded and encased."
From the NRA fact sheet on the bill as transmitted to the Governor for his signature:
http://www.nraila.org/pdfs/PPA Summary 2011 Final Version to Governor.pdf
"Eliminates the prohibition against the possession of uncased, loaded handguns in vehicles, noncommercial aircraft, boats, and ATVs. This expanded freedom applies to both licensees and non-licensees."
Now all those amateur attorneys and professional prosecutors out there can cry and pout all they want about punctuation in the statutes and perverse precedent from vanquished left-wingbat courts, but the intent of the legislature on this matter is clear and has been widely publicized. I'm not saying that this won't require a painful test case for those brave enough to go through the system, but freedom has never been advanced by cowards or bureaucrats.