The way i think would be the fastest way to get xp would be doing four stores on any dificulty above Overkill because it normally would give you at least 66k xp all you need for this is an ECM jammer and you need to find a ATM once you use the ECM on the ATM it will give you enough money to finish the job then wait for the van and escape this takes at least 5 min. You can go for all the extra loot but in the end without all the extra loot you will get at least 141k in spending cash. ?????????