Not sure anyone will ever have the number 1 spot without a fight on their hands.
Also despite having an XE on order I'm not sure it's actually ever attained the number 1 spot.
The 3 series has led this sector for years and that's not just based on industry reviews but 9n sales and owners which aided it's reputation.
I hope the XE lives upto all the hype for obvious reasons as I will have one for the next 4 years (company car) but unfortunately for the XE I will be a tough cookie to please as my current 10 year old BMW will be very hard to match with only economy being beaten by the XE