Urgent purchase advice Please 🙂

Hello, after our last and first car purchase went into my pants, I urgently need advice I looked at an Opel Tigra Twintop, BJ 2006 with almost 51.000 km from the dealer. Here’s my report: An advertisement of the Opel car dealership but sale of a dealer who rented himself there (I think ok). On the phone and on the Internet there should be 4 previous owners (Max. pain limit, is a convertible and can also only be a day registration or something like that). The driver’s seat cannot be pumped up and an audio box at the driver’s seat does not sound good (will be done). It would be a guarantee, TÜV and customer service re-entered. Now he writes in the purchase contract 5 previous owners and tells me there was a day registration (according to the previous owner) with me, unfortunately I could only see the last three. What do you think about it? The last previous owner had him almost 1.5 years. Tomorrow my mum would have signed the purchase contract (all information according to the previous owner) and mailed and we are now really unsure. Offer at mobile.de in Gersthofen almost 5200 €. I would be happy about answers and tips Many greetings