One thing I get a lot of comments on is how easily my cat gets into her crate. This can be achieved relatively easily, believe it or not. Please know that this is a process, but no cat is un-trainable and no cat is doomed to forever hate their crate. It just takes patience on our part!
Your first step should be to make sure the crate fits your cat. While most cats are small, they do not want to feel cramped. Cats also happen to be the most picky animal on this planet, so don't think you're saving yourself by getting the biggest crate available. Too much room and they'll feel vulnerable. Cats truly require the perfect middle ground, so look at the size of your cat and decide what a medium sized crate for them would look like.
Your second step should be to make sure the cat feels comfortable in their crate. One way to make a cat feel comfortable in their crate is for you to purposely place a blanket in their favorite sleeping spots in the house. By doing this, your cat is likely to decide to sleep on top of the blanket and consequently infuse the blanket with their own scent. I would recommend allowing your cat to sleep on this blanket for a week. Then place that blanket inside their crate. What this does is create a familiar feeling to them inside the crate. Another way to create ease inside their crate is to provide them with a small toy. The crate should also be placed somewhere comfortable in the house with the door open so that they feel as though they can come in and out of their crate with no worry.
Your third step should be to create incentive to want to be in the crate. Begin by tapping the top of the crate a few times and giving your cat a treat as it decides to enter the crate on their own. After your cat is in the crate, close the door gently and wait until they notice that the door has been closed. Open the crate back up and give them lots of love (and another treat) as they come out on their own. Continue to do this every day until your cat doesn't seem to mind walking in and out of their crate. By first tapping on the roof of the crate before they walk in and receive a treat, you are creating an audio cue for them to follow in the future. After you've done this for a while, you should be able to just tap on your crate and the kitty will pop right in! Another note: It is vitally important that your cat's crate is never, ever used as a means of punishment!!
Your fourth step should be to make your cat comfortable with movement inside of the crate. Begin by performing step three; however, instead of opening the door, you're going to pick up the crate and walk across the house. Do this for a brief amount of time before you let them out and give them another treat as they are leaving their crate. Continue to do this for slightly longer periods of time. As your cat becomes comfortable with the walking around your house routine, you can begin to make them comfortable with the car by taking them on your normal route inside the house then taking them to your car and giving them a treat as you sit them down and buckle them in. You should do this a few times before you actually take them on a ride.
Your fifth step should be to make your cat comfortable with riding in cars. This is achieved by doing everything in steps one through four and continuing to give treats. Cats can become startled by loud noises so the radio should be turned down as they are becoming accumulated to their changing environment. Don't worry though, if you follow the steps, I have no doubt you'll be back to your usual jam sessions with an additional treat: your cat! It is very important that your crate is strapped into the chair, as well, both for their comfort (who wants to be sliding everywhere at each turn?) and for their safety. If you're questioning how to strap them in, it's as simple as putting the seat belt through the handle on top! Begin each drive with a treat and give them treats as they need them throughout the short drive and of course, give them a treat when you're back into the house. The way I did this for my own cat was to drive her to my dad's house every day while I was at work. His house was only about fifteen minutes from mine. This meant she got two short car rides a day for roughly five days of the week. We did this for roughly three months; however, that was more for cat baby-sitting convenience as kittens cannot be left alone for long periods of time. What it comes down to is that it is really important that your cat is in your car for more than just vet visits and long drives as your cat will begin to associate their crate with unpleasant activities otherwise!
I realize this might seem like a lengthy process and I'll admit, this regimen works much quicker with kittens, but if you stick with it, you'll have a kitty that loves their crate in no time. My cat even takes impromptu naps in hers every once in a while! Good luck and remember: give that kitty a treat!!
