SPOT WELDER ATTACHMENT

I have a spot welder that I got from harbor freight some time ago & it works great. I would love to find prong attachments for it to be able to do the spot welds around the wheel wells. The only 2 places that I cant spot weld are the wheel wells & where the quarter meets the door jamb. Anyone have any ideas where I can find a pair ?
Which model do you have? I'm thinking of getting one. Thankyou.