Don’t lower the car. You won’t even make it off the boat without ripping something off the front end if you are driving it over. If anything, increase the height or stiffen the shocks a bit. Good shocks are a must. If you are entering Targa, having the cage built is the best route. Our tech adviser would be able to suggest the best route on that front. And you’re only allowed 6 tires for the whole event. By having 2 different sets on the car, you are already limiting yourself to a single spare for each set. Once they are used, you’ll then be given time penalties (fairly heavy too) for each additional tire you use. Just use the same tires on the vehicle and that’ll give you a couple spares.