is an 18x8 +35 guaranteed to clear the front brakes of an IS350? The specific wheel I'm looking at is an Enkei TM7. Looks like it has a flat face so I'm assuming it should clear but be tight.

for reference the stock f sport wheels are 18x8 +45

 

Im running 18x10 +25 with no problems

 

It really depends on the Disk type. Each manufactures uses different names of measurement. so you would need to call them and ask if they will clear. With that said, if the wheel is flat face without any lip with 30+ offset, it "should" clear.