yeah mate it is the easiest method - but look on youtube as there is a glitch to do the 5 rolls
easier method
get a car and bomb down the airport run way then clip the yellow caution sign and you'll prob do about 2 rolls, then in the same car do this again another 2 rolls and then again and you'll get the achievement - but make sure you get a brand new car before doing this as the achievement is only gained in the same car
as for the 4 stars just try and out run them on the run way - easier on a motorbike mate