That's actually backwards. 26mm offset + 15mm spacer is 11mm offset. There's a video on utube showing an owner putting 15mm spacers on the rear with Sentas and 20 on the front with Sentas. The problem with too little offset, i.e. wheel farther out is that you can catch the fender lip, bend the fender, puncture the tire.

@Gomes is spot on. Wish you weren't in Idaho @SNAPCHAT . I'd love to have the Sentas. Already running the spacers on my Jupiters. H&R Trak+ 20mm DRM Wheel Adaptor Bolt 5/108 Center Bore 63.3 Stud Thread 12x1.5 ebay, MISHIMOTO 15mm SPACERS MMWS-006-150BK 5X108, 63.3/4, 12X1.2 AMAZON HGA Performance

 

I can't help directly because I have a 5.0 car with the different rear offset, but I will say that there are massive amounts of space in the wheel wells in the front and truly massive amounts of space in the back of these cars. Not 11-inch-wheels-in-front C4 Corvette levels but not far removed. About a month ago I did pretty much the 5.0 XKR-S size/offset for my special ordered wheels in the back and 9.5 ET45s in the front; and while I wasn't brave enough to put my money on the line to try I suspect I could have done the 10.5 ET50 fitment on the front as well now that I actually have them in hand.

 

With pontoons like that, no need to worry about floods.

 

I really liked how my square setup on my Corvette (originally 315/35-17s, later 295/80-18s) drove and the ability to do 4-corner rotations. I did strongly consider doing something similar for this car (with 295/30-20s) to try and make the steering a bit heavier, but since I was going to be changing the steering rack to the F-Type unit and installing Spires springs, plus the lead times/risk with ordering custom offset/bolt pattern wheels if they didn't fit, I decided to go with something more much more aggressive than stock but not that aggressive so I knew it would fit.

 

The stock rear wheels on the 5.0 cars fit wonderfully on the front. Not the 4.2 cars though.

 

I actually used your posts on the subject as my guide for when I was choosing how I wanted the offset on the wheels I got for the front machined.