Get yourself a good gallon jug of water from the convenience store. One that has a screw on lid so it will last longer. Fill that baby up and leave it in your car (or under your car if it will get too hot). When you get back from a ride use it to take a shower in your bibs. Then deck change into fresh clothes. Bring plastic bag for wet clothes.
This is basically what I do for every activity, surf/swim, trail running, cycling etc. I fill empty Tide bottles with water and I have a truck with a camper shell so I donâ€™t use a plastic bag, just toss wetsuit, clothes in a bucket.
For trail running or long trips post activity I take it one step further. I have a big zip lock bag with baby shampoo/wash cloth and a small amount of water and do a wash before rinsing off.
I also have seat covers, I use these guys since thereâ€™re local but you can get cheaper ones online. https://www.wetokole.com/
Train safe & smart