If expenses outweigh the mileage deductible can I use expenses even though I filed mileage last year? Or can we not switch

Yes, you'll be able to switch to the actual expenses method if you own your car and you used the standard mileage rate in the first year that you used your car for business. The rules are different though if you lease your car. If you're leasing your car, you'll need to take the standard rate for the entire lease term.