Milwaukee Area Good Dealer?

[xwing]

Looking for Milwaukee area GMC/Chevy dealership dealing with Duramax/Diesel trucks, who has track record of being Good, and Reasonable with regard to simple mods like Exhaust system and Airfilters not voiding warranty...comments or help appreciated smile.gif

[Kennedy]

Madison too far???

[xwing]

Yes, if I have to leave truck several days for repairs, that is almost 90min from my house. I am getting occasional smoke at idle in drive, which goes away when put in neutral and no smoke just driving, that sounds like bad injector issue from what I read here. I have no mods now really but want an exhaust for better sound, lower EGT etc which should make truck last LONGER if anything, since I plan to keep it forever smile.gif but one dealer service guy waffled when I asked if it would void warranty, wouldn't commit...though if something big goes wrong, 90 min will seem minor compared to potential costs so who is good around Madison anyway??
Thanks!