Tizz, I am in Minnesota driving spring through fall. On rainy days my car stays in the garage. Other than airborne dust, my roof stays fairly clean. I wash the car by hand every couple weeks. Before washing I use this brush attachment (amazon link below) on my shop vac to clean off any loose dirt and dust, and then give it a spray down with the garden hose at the end of the car wash process. I use my electric leaf blower to remove most of the rinse water from the car body and roof, then gently towel dry the roof. When all done I drive a few miles on the freeway to air dry the roof more, then when parked I pop the roof latch and elevate the roof about a foot or so from the windshield to allow air to get down under the base of the roof. Towel dry that base area as needed, down below what is normally exposed. (And read recent threads about cleaning the roof drain filters, too.)
I keep this brush set aside in a plastic bag for use only with the car. I also use the vac to clean the brush itself- pull it off the hose and scrub the bristles over the end of the hose. I also use the same vac brush to wash the top with 303 top cleaner- spray on the cleaner and gently, lightly scrub the top with the vac brush. This works very well, it is a very soft brush.
I'll admit to sealing the roof only twice in 6 summers, using 303 each time. The first time I poured it out from the spray bottle into a container and used a natural bristle brush to apply- pain in the butt. The next time I used large plastic construction waste trash bags (cut on thier side seams to double their size) and masked off the car. I did this by releasing the top, draping the plastic over the windshield and door windows and door panels (you'll need to re-elevate the windows most of the way up), then close the top from outside but not latching it, it stayed closed but loose. I tucked plastic down behind the body panels at the base of the roof, and masked the rear window with blue painter's tape and plastic. This process was its own pain in the butt, but I could now just spray the 303 as intended, which worked well. You do not want this stuff on the painted body. Give the front half of the roof extra attention with your product of choice- that is the most weather beaten area of the roof, both rain and shine.
I found the 303 penetrated the blue tape on the rear window, requiring using a fresh straight razor blade to scrape residue off the glass. Maybe a plastic tape next time. Maybe Frog Tape masking tape?
Yep, a soft top requires work but it is worth it for prolonged service life and good looks. I'll do the full service on mine again next spring.