I'm Catholic and our Deacon rides a motorcycle to church. Our church is also a mix, jeans to suits. The only thing I don't like is the very revealing clothing, especially when the girls would wear super short skirts/shorts and low cut tops to sing in the choir. I know it's Texas, and it's hot outside. These were the styles I saw around town too so I guess it was what was 'in'.
I'd much rather someone come to Mass wearing a plain shirt and decent fitting pair of clean blue jeans (or even a long pair of shorts that reach the knees) compared to the fashion parade I saw coming into Mass, in the Communion line and leaving Mass by females of various ages:
*strapless dresses or shirts
*spaghetti strapped dresses or shirts
*shorts that barely cover the bum, some of them appearing to be nearly skin tight
*skirts or dresses that barely covered the bum
I thought most of them were dressed better for the beach, pool or the street corner compared to Mass. At least I am glad my mother insisted on clothes that had to be neat, clean, decent and modest even if they were not super dressy at times.