I cant speak for Hotrod air or Southern Air but I have a Vintage Air unit purchased in 1993 spent 13 years in the car waiting to get used ,when I fired it up for the first time it blew the foam seals out at me in little pieces for about a month then before the summer was over the squirrel cage fan blade broke in half and I had to tear my dashboard back out to get to it (not fun!) the unit seems really under powered even when on full blow it barely keep the small 34 coupe cool but this was there smallest unit they sold for tight places like behind my coupes dash board and thay dont pull fresh air from outside they recirculate the interior air ,so I would suggest (in Hindsight) purchasing the biggest and upper price scale I could fit in the car and can afford ,these units are built really cheap and simple not like what you would expect to see in a production car. Take some advice if you go cheap like i did make sure you install it in a way that you can service it and possibly remove it in the car. I didn't do that and regretted it ever since.I think you will be alright if you spend a little more than you want to and get a deluxe unit there probably have upgraded seals and components in them.