Bass Pro in Garland (next to Flying Saucer) is having a car show Saturday 4/20 1pm-5pm.
https://mustangsallyproductions.com/...of_Events.html
There's also this one in Richardson which historically has had a large turnout 12pm-4pm.
http://www.heightscarshow.com/
A cruise from one to the other perhaps? Starting in Richardson would probably be prudent. I'll probably get there about 1-ish.