The main strength of "I Picked Up a Star on the Road" is the directing. The editing and pacing are just fantastic. The story is not draggy or confusing, despite multiple flashback scenes. The ending was somewhat rushed, but since it's only a 10 episode drama, it doesn't feel unnatural. The background music was great too. Also, it was hilarious, and it had a balanced mix of slapstick and verbal comedy (although nothing was that deep, there was some darker humor mixed in). I think it's a great drama to watch while doing chores - it doesn't require any real concentration.
In my opinion, the worst faults of this drama were the casting and the script/ story. I've seen both of the main actors in different roles, and these just didn't suit them as well. Overall, the casting wasn't awful: I think the biggest issue with it was the lack of chemistry between the leads. This was the first drama where I felt SLS, and I didn't even really ship the FL with the SL. I'm sure it's hard to create a good love story between a kidnapper and their victim, and I think the writers of IPUASOTR struggled with not making it feel creepy. I don't want to spoil anything, but it just... didn't sit right with me. There were some issues with the consistency of the characters as well. Why does the FL fight (and win) in some parts and then just completely give up and scream in others? I could chalk it up to panic, but she was so focused and cool-headed when she thought she had killed someone, I have a hard time believing she would hesitate to beat someone up if her life was threatened.
Lastly, I am a bit upset that this drama was tagged "political." Almost all of the FLs monetary problems were fixed by the ML. In some parts it bordered on a "rich ML; poor/ weak FL" drama and I think that's where it really let itself down.
Conclusion: I think IPUASOTR is a solid 8.5/10. It's funny and innovative, but I think it fails to reach its potential because of sloppy writing and poor casting.