I'd bet a drop could be due to you paying off that car loan. Although ck gives you a Vantage 3.0 (aka FAKO) score, AFAIK most of the models penalize us for not having an open installment loan. It's common to hear complaints of score drops after paying off car loans. Sounds like you're heading in the right direction. Any effect from inquiries will diminish in a few months, and there'll be none after a year.
In my journey for better numbers, TU goes against all bankcard balances. My first payoff on a CC yielded 14 and 12 pts on EX and EQ, TU gave me 4.