Ultimate motorway cruiser 10k ish v car allowance

New job requires mon-Fri 90 mile round trip on the motorway. Maybe a few days at home where and there so call it c.20k a year.

What is the best option? There is potential of 5k pa allowance but has to meet 130g/km emissions standard. Or disregard that and claim c.45p a mile in personal vehicle.

Thinning 330e to meet allowance restrictions, if not a 330d or A4 diesel.

Any other ideas? More so keen on ideas to meet the emission class…