From experience I would suggest you avoid an internally mounted glass dab antenna, they are rubbish, I know I've tried. On the Zed settled for a glass mount (external) and it's not bad, the internal mount MUST go in the black shaded area at top and centre of the windscreen. If you want absolutely perfectDab reception than go for a replacement body mount, I did this on the company van and travel extensively around the country, absolutely streets ahead of the Zed glass mount. Have a look at Dabonwheels, brilliant range of products and they used to refund even if you ordered the wrong item, has to be unopened obviously. Hope that helps😄