I've got my eye on the 2018 Silverado LTZ right now and appears they are offering pretty good deals. It MSRP's at $50K and some are offering rebates/incentives down to $37K or $38K right now. I've not bought a car in 8 years and my last purchase was used, and so I'm not sure much additional negotiating room I can expect with those types of rebates. Any advice? Thanks.