It's not just carseats, I'm pregnat with my 1st boy after 2 girls and it's hard to find really cute anything for boys, especially without spending an arm and a leg. Not too mention how cliche all the boys stuff is, if you don't like sports and dinosaurs then 65% of what you can buy is cut out. It's so much harder to shop for a boy!
All that I can say is take up sewing. I hate most of what is on the market for boys these days. I've found some great basics at The Children's Place. Nice button down shirts in cotton and linen with nothing printed on them. Levis still look good too. Other than that, make it yourself. BTW car seat covers are pretty easy to make.