guys, how much would it be to darken a tint?already have a llumar diamond 6 6mil security but feels too bright -__-

current VLT all are 70%. would like to darken rear and side windows only to 40-50%.

tint agent appreciate for your responses

it was a LLumar diamond 6. it's 63% VLT if based on spec. but seriously it's still to bright for me. Heat rejection is good though. now thinking to darken it a lil bit more probably 40% - 50% for all except front windshield 

dont know which tint to choose for