Depends on what you want from the car.
The 335is is a good straight line car with the N54 that is easy to mod & takes mods very well.
The 135is is a lot more agile but slower in a straight line & has the less powerful N55 with the PPK-2.
You sit in the 335is but you strap on the 135is. Interior fittings, seats etc are, in 99% of the cases, identical.
Mine both have the same equipment but the price spread between them favored the 135is even though its a convertible. Personally I believe the 335 Coupe is a better looking car. For what its worth the 335is has a 7DCT & the 135is a 6MT. Felt both transmission choices suited the overall type of cars they are.
Last the will both be hard to come by at this point because of the EOP. Dealers would need to swap cars & color/equipment choices will be limited. Good Luck in your search.
BTW I know the gas tank flap is open
