If you think leaving your laptop in your car is a good idea, then by all means, do it with your own. I live in Louisiana where the inside of a car can reach 90-100+ degrees within an hour easily. I'm also a musician and photographer. Often times, I am coming straight to work from or going straight from work to a place where I need either my instrument(s), camera backpack, or school backpack/laptop. Any of those items individually are worth upwards of $1500. Maybe it's because I'm not a pharmacist yet, but to me that's way more money and sentimental value than I'm willing to risk leaving in my car due to theft or temperature. If you can afford to lose that kind of stuff as a pharmacy student, more power to you. The Walgreen's I used to work at (which was in a very bad neighborhood) made a big deal when I brought my sax into the pharmacy (I had a gig right after work) and told me I had to leave it in my car because it didn't fit in a locker. I refused and said I would hold Walgreen's accountable if anything happened to it as a result, and they eventually let me put it in the manager's office.
Also, if I'm playing a gig or going out after work, I don't want to wear my dress clothes or scrubs out and get them all smoky smelling, so I think it's perfectly reasonable to bring a change of clothes to work.