Dude, I hate to say it, but Kansai Airport is on an island about 1 hour south of central Osaka by train. By the time you get to Namba (downtown) you'll have to turn around an d head back to the airport. Trial garage is down that way, but I don't know how to get there. My advice would be to give it a miss this time and organise some car shop tours when you've got more time to spare.