Yes, an 8.5 foot wide trailer is necessary. Length is up to the prospective owner. I do a ton of track days every year. My trailer is 27 ft long bumper pull 10000 lb gross weight capacity.
I wanted the extra length for the stuff I take. The more days you do, the more stuff you’re going to need. I have a generator for the A/C, Cooler, winch, Fuel jug storage, pit bike.
The most important thing that I did (at least in my mind) is that I put ramp overs in mine. It lifts the car 13” inches off of the trailer floor and they run from the rear to the edge of the walking in door in the front of the trailer. I can store 2 sets of tires under the Viper. Might as well take advantage of some of the space above the car that can’t be used. I do NOT use wall style tire storage as I don’t want something coming down accidently and damaging the car. The other advantage is that I can actually work on the underside of the car in the trailer safely. I have had to bleed the clutch, brake lines and an ABS speed sensor.
By having the ramp overs the loading ramps got a bit complicated as they needed to be longer in order to load the car. I also have the obligatory escape door on the left side of the trailer.
