Owing to the fact that your first line has sentence-ending punctuation, the second sentence is completely independent of it, therefore, its first word should be capitalized.
Back in the 1990s, I had an orange Nissan pickup. When it came time to replace the tires, the ones Big O Tires sold me ended up being white walls. (Uh... I don't think so!). I had them flip the white to the inside.
Yeah they should make a comeback they look pretty cool plus they somehow make a vehicle go faster (sort of like how chrome somehow makes vehicles go faster). I bet with all the new cleaning products on the market it would be easy to keep the whitewalls looking clean. Cheers!