Wire relay for heated mirrors

im putting heated mirrors on my expedition and i need to know how to wire them up do i need a relay? if so how would i wire both the morrors into a relay so when i flip a switch they will heat up and when i flip the switch back they will shut off

30 - heated mirrors (+) 87 - constant 12V(+) fused (10A or 15A, check their draw) 86 - chassis ground (-) 85 - to switch then to ignition 12V(+) fused (3A)

now would it be better (I dont know if i can even do it this way )but someone told me to get a 5 blades relay and hook one of the mirrors up to the 87a middle one and the other to the other blade or do i have to hook both the hot wires from the mirrors to the one blade on the relay now the mirrors have just the hot and ground on them

Both to 30, that's why I used heated mirrors. You can get 5 blades relay but the middle 87a will be unused and should be cover up. 87a is only needed when you want to do something to the mirrors when the relay is at non-energized state. Note, 87a connects to 30 when idling and 87 to 30 when energized. That said, that person who told you about using 87a are merely clueless.