Canadian Ciizen Applying for J1 Visa

I am a Canadian citizen and have been hired by an organization in the US as an intern/trainee. I have since filled out an extensive application for J1 Visa and sent it back to the host company, they've sent it to the sponsor and now I am getting it back from the sponsor with the necessary forms. Both the host and the sponsor have told me that I need to make an appointment at a US consulate to apply for the visa. I have since been told here in Canada that I just need to go to a Port of Entry on my way down. Is this true? Do I need to have anything other than the completed application and my passport? Is it common to be denied a J1 Visa? It seems so uncertain to make my way down without knowing for sure that I am going to get the visa . I am also planning to drive my (Canadian) car down and wondering if this is allowed. The internship is 5 months long. Thanks!

Most non-immigrant visas for Canadians can be applied for directly at the border, no need for a consulate visit. However, you may just want to check the US consulate website for whichever is closes to you, and they'll have a list on there of which visas they process.

Yes, you can take your car down for a 5 month visit.

You don't need a visa if you're a Canadian citizen for J-1, I can't remember what the form is called, DS-2019 or something like that? You present that and any other supporting documentation and your passport or NEXUS card at the POE.

Only a handful of non-immigrant categories require visas for Canadians, E and K being the most common.

Your car is no problem, only becomes complicated if you stay over a year.

There's no reason you would be denied, the only reasons would be if you have been convicted of something that's listed in CPIC, have been previously denied or banned from entry, or there's something wrong with the DS-2019.