Most EFFICIENT WAY OF DOING IT****
Start bot,finish HS TE
Go to safehouse
CONSTANTLY clean your inventory while botting.For every 10 you clean,5-6 will come back,this is normal because bot is adding while your deleting

I Do it on a 6-1 routine.For every 6 cleans to skill inventory I do 1 to performance part inventory.Because you get a heck of alot more skills than parts.Headsup,you will get a crapload of PRO tires,like tons of them.
gl hf