checkout page critique please

please visit this page (http://www.guitarstorage.com/shop/studio-deluxe-guitar-case-rack/), add one of the products to the cart, and provide some feedback on how I can best streamline the Cart page.

Or just checkout this screenshot (http://www.screenshots.cc/original/59102/6h3ek).

The biggest problem i have is figuring out how to stress to customers that they need to enter their zip code before they click the "Proceed to Checkout" button so they'll know in advance what the shipping is going to be.

There's a lot of stuff going on, on this page, and i dont want it to get lost in the shuffle.

Please advise. thanks in advance.

I'd experiment with the placement. It gets lost in the shuffle with the apply coupon thing.

A red arrow pointing to it on the side might work. You could have it move along as one goes through each step until it's time to checkout.

The way the Proceed to Checkout button flashes or shines is distracting. Removing the shine or flash could make people less likely to click it before entering their zip.

You could also just have the zip on that page, but have the coupon on a separate one, so the button you click on the page in the screenshot would just say next page, and then it'd be the coupon, or not, and then they click proceed to checkout.

Personally, I'd work with rearranging the zip input, and the red arrow.

Hope that helps!