How much wider is an E70 than an E53?

[TowX]

I'm looking for a measurement from outer edge of the driver's mirror to the outer edge of the passenger's mirror.

Have a 4.4 E53 but it isn't wide enough to safely tow my new enclosed race car trailer. I can't even remotely see around it. I measured it at 84" from tip to tip, but the trailer is 102" wide so mostly I'm seeing just the trailer in the side mirrors. I picked up some CIPA mirror extensions but the mirrors vibrate so badly at highway speeds that they're worthless. Considering an '08 E70 4.8 with Sport, 20", Nav, Premium etc. But I can't find a spec that gives mirror dimensions to see if it's significantly wider than the E53. Otherwise I'll likely need to get a Yukon Denali or something that size to safely tow the trailer on the multi-state trips this summer.